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2022-12-12Merge tag 'printk-for-6.2' of ↵Linus Torvalds10-26/+90
git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk updates from Petr Mladek: - Add NMI-safe SRCU reader API. It uses atomic_inc() instead of this_cpu_inc() on strong load-store architectures. - Introduce new console_list_lock to synchronize a manipulation of the list of registered consoles and their flags. This is a first step in removing the big-kernel-lock-like behavior of console_lock(). This semaphore still serializes console->write() calbacks against: - each other. It primary prevents potential races between early and proper console drivers using the same device. - suspend()/resume() callbacks and init() operations in some drivers. - various other operations in the tty/vt and framebufer susbsystems. It is likely that console_lock() serializes even operations that are not directly conflicting with the console->write() callbacks here. This is the most complicated big-kernel-lock aspect of the console_lock() that will be hard to untangle. - Introduce new console_srcu lock that is used to safely iterate and access the registered console drivers under SRCU read lock. This is a prerequisite for introducing atomic console drivers and console kthreads. It will reduce the complexity of serialization against normal consoles and console_lock(). Also it should remove the risk of deadlock during critical situations, like Oops or panic, when only atomic consoles are registered. - Check whether the console is registered instead of enabled on many locations. It was a historical leftover. - Cleanly force a preferred console in xenfb code instead of a dirty hack. - A lot of code and comment clean ups and improvements. * tag 'printk-for-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (47 commits) printk: htmldocs: add missing description tty: serial: sh-sci: use setup() callback for early console printk: relieve console_lock of list synchronization duties tty: serial: kgdboc: use console_list_lock to trap exit tty: serial: kgdboc: synchronize tty_find_polling_driver() and register_console() tty: serial: kgdboc: use console_list_lock for list traversal tty: serial: kgdboc: use srcu console list iterator proc: consoles: use console_list_lock for list iteration tty: tty_io: use console_list_lock for list synchronization printk, xen: fbfront: create/use safe function for forcing preferred netconsole: avoid CON_ENABLED misuse to track registration usb: early: xhci-dbc: use console_is_registered() tty: serial: xilinx_uartps: use console_is_registered() tty: serial: samsung_tty: use console_is_registered() tty: serial: pic32_uart: use console_is_registered() tty: serial: earlycon: use console_is_registered() tty: hvc: use console_is_registered() efi: earlycon: use console_is_registered() tty: nfcon: use console_is_registered() serial_core: replace uart_console_enabled() with uart_console_registered() ...
2022-12-02tty: serial: sh-sci: use setup() callback for early consoleJohn Ogness1-4/+16
When setting up the early console, the setup() callback of the regular console is used. It is called manually before registering the early console instead of providing a setup() callback for the early console. This is probably because the early setup needs a different @options during the early stage. The issue here is that the setup() callback is called without the console_list_lock held and functions such as uart_set_options() expect that. Rather than manually calling the setup() function before registering, provide an early console setup() callback that will use the different early options. This ensures that the error checking, ordering, and locking context when setting up the early console are correct. Since this early console can only be registered via the earlyprintk= parameter, the @options argument of the setup() callback will always be NULL. Rather than simply ignoring the argument, add a WARN_ON() to get our attention in case the setup() callback semantics should change in the future. Note that technically the current implementation works because it is only used in early boot. And since the early console setup is performed before registering, it cannot race with anything and thus does not need any locking. However, longterm maintenance is easier when drivers rely on the subsystem API rather than manually implementing steps that could cause breakage in the future. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-41-john.ogness@linutronix.de
2022-12-02tty: serial: kgdboc: use console_list_lock to trap exitJohn Ogness1-3/+3
kgdboc_earlycon_init() uses the console_lock to ensure that no consoles are unregistered until the kgdboc_earlycon is setup. The console_list_lock should be used instead because list synchronization responsibility will be removed from the console_lock in a later change. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-39-john.ogness@linutronix.de
2022-12-02tty: serial: kgdboc: synchronize tty_find_polling_driver() and ↵John Ogness1-4/+12
register_console() Calling tty_find_polling_driver() can lead to uart_set_options() being called (via the poll_init() callback of tty_operations) to configure the uart. But uart_set_options() can also be called by register_console() (via the setup() callback of console). Take the console_list_lock to synchronize against register_console() and also use it for console list traversal. This also ensures the console list cannot change until the polling console has been chosen. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-38-john.ogness@linutronix.de
2022-12-02tty: serial: kgdboc: use console_list_lock for list traversalJohn Ogness1-0/+12
configure_kgdboc() uses the console_lock for console list iteration. Use the console_list_lock instead because list synchronization responsibility will be removed from the console_lock in a later change. The SRCU iterator could have been used here, but a later change will relocate the locking of the console_list_lock to also provide synchronization against register_console(). Note, the console_lock is still needed to serialize the device() callback with other console operations. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-37-john.ogness@linutronix.de
2022-12-02tty: serial: kgdboc: use srcu console list iteratorJohn Ogness1-2/+8
Use srcu console list iteration for safe console list traversal. Note that this is a preparatory change for when console_lock no longer provides synchronization for the console list. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-36-john.ogness@linutronix.de
2022-12-02tty: tty_io: use console_list_lock for list synchronizationJohn Ogness1-6/+12
show_cons_active() uses the console_lock to gather information on registered consoles. It requires that no consoles are unregistered until it is finished. The console_list_lock should be used because list synchronization responsibility will be removed from the console_lock in a later change. Note, the console_lock is still needed to serialize the device() callback with other console operations. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-34-john.ogness@linutronix.de
2022-12-02tty: serial: xilinx_uartps: use console_is_registered()John Ogness1-1/+1
It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-30-john.ogness@linutronix.de
2022-12-02tty: serial: samsung_tty: use console_is_registered()John Ogness1-1/+1
It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-29-john.ogness@linutronix.de
2022-12-02tty: serial: pic32_uart: use console_is_registered()John Ogness1-1/+1
It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-28-john.ogness@linutronix.de
2022-12-02tty: serial: earlycon: use console_is_registered()John Ogness1-2/+2
It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-27-john.ogness@linutronix.de
2022-12-02tty: hvc: use console_is_registered()John Ogness1-2/+2
It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-26-john.ogness@linutronix.de
2022-12-02serial_core: replace uart_console_enabled() with uart_console_registered()John Ogness3-9/+9
All users of uart_console_enabled() really want to know if a console is registered. It is not reliable to check for CON_ENABLED in order to identify if a console is registered. Use console_is_registered() instead. A _locked() variant is provided because uart_set_options() is always called with the console_list_lock held and must check if a console is registered in order to synchronize with kgdboc. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-23-john.ogness@linutronix.de
2022-12-02tty: tty_io: document console_lock usageJohn Ogness1-0/+10
show_cons_active() uses the console_lock to gather information on registered consoles. Since the console_lock is being used for multiple reasons, explicitly document these reasons. This will be useful when the console_lock is split into fine-grained locking. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-10-john.ogness@linutronix.de
2022-12-02tty: serial: kgdboc: document console_lock usageJohn Ogness1-0/+8
kgdboc_earlycon_init() uses the console_lock to ensure that no consoles are unregistered until the kgdboc_earlycon is setup. This is necessary because the trapping of the exit() callback assumes that the exit() callback is not called before the trap is setup. Explicitly document this non-typical console_lock usage. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-9-john.ogness@linutronix.de
2022-12-02serial: kgdboc: Lock console list in probe functionThomas Gleixner1-0/+2
Unprotected list walks are not necessarily safe. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20221116162152.193147-2-john.ogness@linutronix.de
2022-11-18Merge tag 'tty-6.1-rc6' of ↵Linus Torvalds6-88/+136
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver fixes from Greg KH: "Here are a number of small tty and serial driver fixes for 6.1-rc6. They all resolve reported problems: - kernel doc build problems with the -rc1 serial driver documentation update - n_gsm reported problems - imx serial driver missing callback - lots of tiny 8250 driver fixes for reported issues. All of these have been in linux-next for over a week with no reported problems" * tag 'tty-6.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: docs/driver-api/miscellaneous: Remove kernel-doc of serial_core.c serial: 8250: Flush DMA Rx on RLSI serial: 8250_lpss: Use 16B DMA burst with Elkhart Lake serial: 8250_lpss: Configure DMA also w/o DMA filter serial: 8250: Fall back to non-DMA Rx if IIR_RDI occurs tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_send Revert "tty: n_gsm: replace kicktimer with delayed_work" Revert "tty: n_gsm: avoid call of sleeping functions from atomic context" serial: imx: Add missing .thaw_noirq hook tty: serial: fsl_lpuart: don't break the on-going transfer when global reset serial: 8250: omap: Flush PM QOS work on remove serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove() serial: 8250_omap: remove wait loop from Errata i202 workaround serial: 8250: omap: Fix missing PM runtime calls for omap8250_set_mctrl() serial: 8250: 8250_omap: Avoid RS485 RTS glitch on ->set_termios()
2022-11-09serial: 8250: Flush DMA Rx on RLSIIlpo Järvinen1-2/+1
Returning true from handle_rx_dma() without flushing DMA first creates a data ordering hazard. If DMA Rx has handled any character at the point when RLSI occurs, the non-DMA path handles any pending characters jumping them ahead of those characters that are pending under DMA. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: <stable@vger.kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-5-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250_lpss: Use 16B DMA burst with Elkhart LakeIlpo Järvinen1-0/+2
Configure DMA to use 16B burst size with Elkhart Lake. This makes the bus use more efficient and works around an issue which occurs with the previously used 1B. The fix was initially developed by Srikanth Thokala and Aman Kumar. This together with the previous config change is the cleaned up version of the original fix. Fixes: 0a9410b981e9 ("serial: 8250_lpss: Enable DMA on Intel Elkhart Lake") Cc: <stable@vger.kernel.org> # serial: 8250_lpss: Configure DMA also w/o DMA filter Reported-by: Wentong Wu <wentong.wu@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250_lpss: Configure DMA also w/o DMA filterIlpo Järvinen1-4/+11
If the platform doesn't use DMA device filter (as is the case with Elkhart Lake), whole lpss8250_dma_setup() setup is skipped. This results in skipping also *_maxburst setup which is undesirable. Refactor lpss8250_dma_setup() to configure DMA even if filter is not setup. Cc: stable <stable@kernel.org> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-09serial: 8250: Fall back to non-DMA Rx if IIR_RDI occursIlpo Järvinen1-0/+4
DW UART sometimes triggers IIR_RDI during DMA Rx when IIR_RX_TIMEOUT should have been triggered instead. Since IIR_RDI has higher priority than IIR_RX_TIMEOUT, this causes the Rx to hang into interrupt loop. The problem seems to occur at least with some combinations of small-sized transfers (I've reproduced the problem on Elkhart Lake PSE UARTs). If there's already an on-going Rx DMA and IIR_RDI triggers, fall graciously back to non-DMA Rx. That is, behave as if IIR_RX_TIMEOUT had occurred. 8250_omap already considers IIR_RDI similar to this change so its nothing unheard of. Fixes: 75df022b5f89 ("serial: 8250_dma: Fix RX handling") Cc: <stable@vger.kernel.org> Co-developed-by: Srikanth Thokala <srikanth.thokala@intel.com> Signed-off-by: Srikanth Thokala <srikanth.thokala@intel.com> Co-developed-by: Aman Kumar <aman.kumar@intel.com> Signed-off-by: Aman Kumar <aman.kumar@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20221108121952.5497-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_sendDuoming Zhou1-1/+1
The function gsm_dlci_t1() is a timer handler that runs in an atomic context, but it calls "kzalloc(..., GFP_KERNEL)" that may sleep. As a result, the sleep-in-atomic-context bug will happen. The process is shown below: gsm_dlci_t1() gsm_dlci_open() gsm_modem_update() gsm_modem_upd_via_msc() gsm_control_send() kzalloc(sizeof(.., GFP_KERNEL) //may sleep This patch changes the gfp_t parameter of kzalloc() from GFP_KERNEL to GFP_ATOMIC in order to mitigate the bug. Fixes: e1eaea46bb40 ("tty: n_gsm line discipline") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Link: https://lore.kernel.org/r/20221002040709.27849-1-duoming@zju.edu.cn Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03Revert "tty: n_gsm: replace kicktimer with delayed_work"Fedor Pchelkin1-8/+8
This reverts commit c9ab053e56ce13a949977398c8edc12e6c02fc95. The above commit is reverted as it was a prerequisite for tx_mutex introduction and tx_mutex has been removed as it does not correctly work in order to protect tx data. Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Reviewed-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20221008110221.13645-3-pchelkin@ispras.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03Revert "tty: n_gsm: avoid call of sleeping functions from atomic context"Fedor Pchelkin1-24/+29
This reverts commit 902e02ea9385373ce4b142576eef41c642703955. The above commit is reverted as the usage of tx_mutex seems not to solve the problem described in 902e02ea9385 ("tty: n_gsm: avoid call of sleeping functions from atomic context") and just moves the bug to another place. Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Reviewed-by: Daniel Starke <daniel.starke@siemens.com> Link: https://lore.kernel.org/r/20221008110221.13645-2-pchelkin@ispras.ru Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: imx: Add missing .thaw_noirq hookShawn Guo1-0/+1
The following warning is seen with non-console UART instance when system hibernates. [ 37.371969] ------------[ cut here ]------------ [ 37.376599] uart3_root_clk already disabled [ 37.380810] WARNING: CPU: 0 PID: 296 at drivers/clk/clk.c:952 clk_core_disable+0xa4/0xb0 ... [ 37.506986] Call trace: [ 37.509432] clk_core_disable+0xa4/0xb0 [ 37.513270] clk_disable+0x34/0x50 [ 37.516672] imx_uart_thaw+0x38/0x5c [ 37.520250] platform_pm_thaw+0x30/0x6c [ 37.524089] dpm_run_callback.constprop.0+0x3c/0xd4 [ 37.528972] device_resume+0x7c/0x160 [ 37.532633] dpm_resume+0xe8/0x230 [ 37.536036] hibernation_snapshot+0x288/0x430 [ 37.540397] hibernate+0x10c/0x2e0 [ 37.543798] state_store+0xc4/0xd0 [ 37.547203] kobj_attr_store+0x1c/0x30 [ 37.550953] sysfs_kf_write+0x48/0x60 [ 37.554619] kernfs_fop_write_iter+0x118/0x1ac [ 37.559063] new_sync_write+0xe8/0x184 [ 37.562812] vfs_write+0x230/0x290 [ 37.566214] ksys_write+0x68/0xf4 [ 37.569529] __arm64_sys_write+0x20/0x2c [ 37.573452] invoke_syscall.constprop.0+0x50/0xf0 [ 37.578156] do_el0_svc+0x11c/0x150 [ 37.581648] el0_svc+0x30/0x140 [ 37.584792] el0t_64_sync_handler+0xe8/0xf0 [ 37.588976] el0t_64_sync+0x1a0/0x1a4 [ 37.592639] ---[ end trace 56e22eec54676d75 ]--- On hibernating, pm core calls into related hooks in sequence like: .freeze .freeze_noirq .thaw_noirq .thaw With .thaw_noirq hook being absent, the clock will be disabled in a unbalanced call which results the warning above. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_thaw clk_disable_unprepare() Adding the missing .thaw_noirq hook as imx_uart_resume_noirq() will have the call sequence corrected as below and thus fix the warning. imx_uart_freeze() clk_prepare_enable() imx_uart_suspend_noirq() clk_disable() imx_uart_resume_noirq() clk_enable() imx_uart_thaw clk_disable_unprepare() Fixes: 09df0b3464e5 ("serial: imx: fix endless loop during suspend") Reviewed-by: Martin Kaiser <martin@kaiser.cx> Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Link: https://lore.kernel.org/r/20221012121353.2346280-1-shawn.guo@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03tty: serial: fsl_lpuart: don't break the on-going transfer when global resetSherry Sun1-27/+49
lpuart_global_reset() shouldn't break the on-going transmit engine, need to recover the on-going data transfer after reset. This can help earlycon here, since commit 60f361722ad2 ("serial: fsl_lpuart: Reset prior to registration") moved lpuart_global_reset() before uart_add_one_port(), earlycon is writing during global reset, as global reset will disable the TX and clear the baud rate register, which caused the earlycon cannot work any more after reset, needs to restore the baud rate and re-enable the transmitter to recover the earlycon write. Also move the lpuart_global_reset() down, then we can reuse the lpuart32_tx_empty() without declaration. Fixes: bd5305dcabbc ("tty: serial: fsl_lpuart: do software reset for imx7ulp and imx8qxp") Signed-off-by: Sherry Sun <sherry.sun@nxp.com> Link: https://lore.kernel.org/r/20221024085844.22786-1-sherry.sun@nxp.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: omap: Flush PM QOS work on removeTony Lindgren1-0/+1
Rebinding 8250_omap in a loop will at some point produce a warning for kernel/power/qos.c:296 cpu_latency_qos_update_request() with error "cpu_latency_qos_update_request called for unknown object". Let's flush the possibly pending PM QOS work scheduled from omap8250_runtime_suspend() before we disable runtime PM. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20221028110044.54719-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: omap: Fix unpaired pm_runtime_put_sync() in omap8250_remove()Tony Lindgren1-0/+5
On remove, we get an error for "Runtime PM usage count underflow!". I guess this driver is mostly built-in, and this issue has gone unnoticed for a while. Somehow I did not catch this issue with my earlier fix done with commit 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime"). Fixes: 4e0f5cc65098 ("serial: 8250_omap: Fix probe and remove for PM runtime") Signed-off-by: Tony Lindgren <tony@atomide.com> Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Link: https://lore.kernel.org/r/20221028105813.54290-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250_omap: remove wait loop from Errata i202 workaroundMatthias Schiffer1-17/+0
We were occasionally seeing the "Errata i202: timedout" on an AM335x board when repeatedly opening and closing a UART connected to an active sender. As new input may arrive at any time, it is possible to miss the "RX FIFO empty" condition, forcing the loop to wait until it times out. Nothing in the i202 Advisory states that such a wait is even necessary; other FIFO clear functions like serial8250_clear_fifos() do not wait either. For this reason, it seems safe to remove the wait, fixing the mentioned issue. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Link: https://lore.kernel.org/r/20221013112339.2540767-1-matthias.schiffer@ew.tq-group.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: omap: Fix missing PM runtime calls for omap8250_set_mctrl()Tony Lindgren1-2/+20
There are cases where omap8250_set_mctrl() may get called after the UART has already autoidled causing an asynchronous external abort. This can happen on ttyport_open(): mem_serial_in from omap8250_set_mctrl+0x38/0xa0 omap8250_set_mctrl from uart_update_mctrl+0x4c/0x58 uart_update_mctrl from uart_dtr_rts+0x60/0xa8 uart_dtr_rts from tty_port_block_til_ready+0xd0/0x2a8 tty_port_block_til_ready from uart_open+0x14/0x1c uart_open from ttyport_open+0x64/0x148 And on ttyport_close(): omap8250_set_mctrl from uart_update_mctrl+0x3c/0x48 uart_update_mctrl from uart_dtr_rts+0x54/0x9c uart_dtr_rts from tty_port_shutdown+0x78/0x9c tty_port_shutdown from tty_port_close+0x3c/0x74 tty_port_close from ttyport_close+0x40/0x58 It can also happen on disassociate_ctty() calling uart_shutdown() that ends up calling omap8250_set_mctrl(). Let's fix the issue by adding missing PM runtime calls to omap8250_set_mctrl(). To do this, we need to add __omap8250_set_mctrl() that can be called from both omap8250_set_mctrl(), and from runtime PM resume path when restoring the registers. Fixes: 61929cf0169d ("tty: serial: Add 8250-core based omap driver") Reported-by: Merlijn Wajer <merlijn@wizzup.org> Reported-by: Romain Naour <romain.naour@smile.fr> Reported-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Tested-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Depends-on: dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") Link: https://lore.kernel.org/r/20221024063613.25943-1-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-03serial: 8250: 8250_omap: Avoid RS485 RTS glitch on ->set_termios()Lukas Wunner1-3/+4
RS485-enabled UART ports on TI Sitara SoCs with active-low polarity exhibit a Transmit Enable glitch on ->set_termios(): omap8250_restore_regs(), which is called from omap_8250_set_termios(), sets the TCRTLR bit in the MCR register and clears all other bits, including RTS. If RTS uses active-low polarity, it is now asserted for no reason. The TCRTLR bit is subsequently cleared by writing up->mcr to the MCR register. That variable is always zero, so the RTS bit is still cleared (incorrectly so if RTS is active-high). (up->mcr is not, as one might think, a cache of the MCR register's current value. Rather, it only caches a single bit of that register, the AFE bit. And it only does so if the UART supports the AFE bit, which OMAP does not. For details see serial8250_do_set_termios() and serial8250_do_set_mctrl().) Finally at the end of omap8250_restore_regs(), the MCR register is restored (and RTS deasserted) by a call to up->port.ops->set_mctrl() (which equals serial8250_set_mctrl()) and serial8250_em485_stop_tx(). So there's an RTS glitch between setting TCRTLR and calling serial8250_em485_stop_tx(). Avoid by using a read-modify-write when setting TCRTLR. While at it, drop a redundant initialization of up->mcr. As explained above, the variable isn't used by the driver and it is already initialized to zero because it is part of the static struct serial8250_ports[] declared in 8250_core.c. (Static structs are initialized to zero per section 6.7.8 nr. 10 of the C99 standard.) Cc: Jan Kiszka <jan.kiszka@siemens.com> Cc: Su Bao Cheng <baocheng.su@siemens.com> Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/6554b0241a2c7fd50f32576fdbafed96709e11e8.1664278942.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-21parisc/serial: Rename 8250_gsc.c to 8250_parisc.cHelge Deller3-2/+2
The file name of this driver is misleading - it handles various serial ports on parisc machines, not just such on the GSC bus. Rename the file to make this clearer. Suggested-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-21parisc: Make 8250_gsc driver dependend on CONFIG_PARISCHelge Deller1-1/+1
Although the name of the driver 8250_gsc.c suggests that it handles only serial ports on the GSC bus, it does handle serial ports listed in the parisc machine inventory as well, e.g. the serial ports in a C8000 PCI-only workstation. Change the dependency to CONFIG_PARISC, so that the driver gets included in the kernel even if CONFIG_GSC isn't set. Reported-by: Mikulas Patocka <mpatocka@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-14Merge tag 'parisc-for-6.1-1' of ↵Linus Torvalds1-15/+0
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc updates from Helge Deller: "Fixes: - When we added basic vDSO support in kernel 5.18 we introduced a bug which prevented a mmap() of graphic card memory. This is because we used the DMB (data memory break trap bit) page flag as special-bit, but missed to clear that bit when loading the TLB. - Graphics card memory size was not correctly aligned - Spelling fixes (from Colin Ian King) Enhancements: - PDC console (which uses firmware calls) now rewritten as early console - Reduced size of alternative tables" * tag 'parisc-for-6.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Fix spelling mistake "mis-match" -> "mismatch" in eisa driver parisc: Fix userspace graphics card breakage due to pgtable special bit parisc: fbdev/stifb: Align graphics memory size to 4MB parisc: Convert PDC console to an early console parisc: Reduce kernel size by packing alternative tables
2022-10-11parisc: Convert PDC console to an early consoleHelge Deller1-15/+0
Rewrite the PDC console to become an early console. Beside the fact that now boot information is visible until another (text- or graphics) console takes over, this benefits as well machines with a yet-unsupported STI console and kgdb. Signed-off-by: Helge Deller <deller@gmx.de>
2022-10-08Merge tag 'tty-6.1-rc1' of ↵Linus Torvalds105-696/+849
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the big set of TTY and Serial driver updates for 6.1-rc1. Lots of cleanups in here, no real new functionality this time around, with the diffstat being that we removed more lines than we added! Included in here are: - termios unification cleanups from Al Viro, it's nice to finally get this work done - tty serial transmit cleanups in various drivers in preparation for more cleanup and unification in future releases (that work was not ready for this release) - n_gsm fixes and updates - ktermios cleanups and code reductions - dt bindings json conversions and updates for new devices - some serial driver updates for new devices - lots of other tiny cleanups and janitorial stuff. Full details in the shortlog. All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (102 commits) serial: cpm_uart: Don't request IRQ too early for console port tty: serial: do unlock on a common path in altera_jtaguart_console_putc() tty: serial: unify TX space reads under altera_jtaguart_tx_space() tty: serial: use FIELD_GET() in lqasc_tx_ready() tty: serial: extend lqasc_tx_ready() to lqasc_console_putchar() tty: serial: allow pxa.c to be COMPILE_TESTed serial: stm32: Fix unused-variable warning tty: serial: atmel: Add COMMON_CLK dependency to SERIAL_ATMEL serial: 8250: Fix restoring termios speed after suspend serial: Deassert Transmit Enable on probe in driver-specific way serial: 8250_dma: Convert to use uart_xmit_advance() serial: 8250_omap: Convert to use uart_xmit_advance() MAINTAINERS: Solve warning regarding inexistent atmel-usart binding serial: stm32: Deassert Transmit Enable on ->rs485_config() serial: ar933x: Deassert Transmit Enable on ->rs485_config() tty: serial: atmel: Use FIELD_PREP/FIELD_GET tty: serial: atmel: Make the driver aware of the existence of GCLK tty: serial: atmel: Only divide Clock Divisor if the IP is USART tty: serial: atmel: Separate mode clearing between UART and USART dt-bindings: serial: atmel,at91-usart: Add gclk as a possible USART clock ...
2022-10-06Merge tag 'arm-soc-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/socLinus Torvalds1-3/+0
Pull ARM SoC updates from Arnd Bergmann: "The main changes this time are for the organization of the Kconfig files, introducing per-vendor top-level options on arm64 to match those on arm32, and making the platform selection on arm32 more uniform, in particular for the remaining StrongARM platforms that still have a couple of special cases compared to the more recent ones. I also did a cleanup of the old Footbridge platform, which was the last holdout for the phys_to_dma()/dma_to_phys() interface that is now completely gone from arm32, completing work started by Christoph Hellwig" * tag 'arm-soc-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (21 commits) ARM: aspeed: Kconfig: Fix indentation ARM: Drop CMDLINE_* dependency on ATAGS ARM: Drop CMDLINE_FORCE dependency on !ARCH_MULTIPLATFORM ARM: s3c: remove orphan declarations from arch/arm/mach-s3c/devs.h pxa: Drop if with an always false condition ARM: orion: fix include path ARM: shmobile: Drop selecting SOC_BUS arm64: renesas: Drop selecting SOC_BUS ARM: disallow PCI with MMU=n again ARM: footbridge: remove custom DMA address handling MAINTAINERS: Add BCM4908 maintainer to BCMBCA entry ARM: footbridge: move isa-dma support into footbridge ARM: footbridge: remove leftover from personal-server ARM: footbridge: remove addin mode arm64: Kconfig.platforms: Group NXP platforms together arm64: Kconfig.platforms: Re-organized Broadcom menu ARM: make ARCH_MULTIPLATFORM user-visible ARM: fix XIP_KERNEL dependencies ARM: Kconfig: clean up platform selection ARM: simplify machdirs/platdirs handling ...
2022-10-06Merge tag 'arm-drivers-6.1' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull ARM driver updates from Arnd Bergmann: "The drivers branch for 6.1 is a bit larger than for most releases. Most of the changes come from SoC maintainers for the drivers/soc subsystem: - A new driver for error handling on the NVIDIA Tegra 'control backbone' bus. - A new driver for Qualcomm LLCC/DDR bandwidth measurement - New Rockchip rv1126 and rk3588 power domain drivers - DT binding updates for memory controllers, older Rockchip SoCs, various Mediatek devices, Qualcomm SCM firmware - Minor updates to Hisilicon LPC bus, the Allwinner SRAM driver, the Apple rtkit firmware driver, Tegra firmware - Minor updates for SoC drivers (Samsung, Mediatek, Renesas, Tegra, Qualcomm, Broadcom, NXP, ...) There are also some separate subsystem with downstream maintainers that merge updates this way: - Various updates and new drivers in the memory controller subsystem for Mediatek and Broadcom SoCs - Small set of changes in preparation to add support for FF-A v1.1 specification later, in the Arm FF-A firmware subsystem - debugfs support in the PSCI firmware subsystem" * tag 'arm-drivers-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (149 commits) ARM: remove check for CONFIG_DEBUG_LL_SER3 firmware/psci: Add debugfs support to ease debugging firmware/psci: Print a warning if PSCI doesn't accept PC mode dt-bindings: memory: snps,dw-umctl2-ddrc: Extend schema with IRQs/resets/clocks props dt-bindings: memory: snps,dw-umctl2-ddrc: Replace opencoded numbers with macros dt-bindings: memory: snps,dw-umctl2-ddrc: Use more descriptive device name dt-bindings: memory: synopsys,ddrc-ecc: Detach Zynq DDRC controller support soc: sunxi: sram: Add support for the D1 system control soc: sunxi: sram: Export the LDO control register soc: sunxi: sram: Save a pointer to the OF match data soc: sunxi: sram: Return void from the release function soc: apple: rtkit: Add apple_rtkit_poll soc: imx: add i.MX93 media blk ctrl driver soc: imx: add i.MX93 SRC power domain driver soc: imx: imx8m-blk-ctrl: Use genpd_xlate_onecell soc: imx: imx8mp-blk-ctrl: handle PCIe PHY resets soc: imx: imx8m-blk-ctrl: add i.MX8MP VPU blk ctrl soc: imx: add i.MX8MP HDMI blk ctrl HDCP/HRV_MWR soc: imx: add icc paths for i.MX8MP hsio/hdmi blk ctrl soc: imx: add icc paths for i.MX8MP media blk ctrl ...
2022-09-30serial: cpm_uart: Don't request IRQ too early for console portChristophe Leroy1-12/+10
The following message is seen during boot and the activation of console port gets delayed until normal serial ports activation. [ 0.001346] irq: no irq domain found for pic@930 ! The console port doesn't need irq, perform irq reservation later, during cpm_uart probe. While at it, don't use NO_IRQ but 0 which is the value returned by irq_of_parse_and_map() in case of error. By chance powerpc's NO_IRQ has value 0 but on some architectures it is -1. Fixes: 14d893fc6846 ("powerpc/8xx: Convert CPM1 interrupt controller to platform_device") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Link: https://lore.kernel.org/r/8bed0f30c2e9ef16ae64fb1243a16d54a48eb8da.1664526717.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30tty: serial: do unlock on a common path in altera_jtaguart_console_putc()Jiri Slaby1-2/+3
port->lock is unlocked in each branch in altera_jtaguart_console_putc(), so do it before the "if". "status" needs not be under the lock, as the register was already read. Cc: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20220927111819.18516-4-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30tty: serial: unify TX space reads under altera_jtaguart_tx_space()Jiri Slaby1-11/+16
TX space reads from the control register are performed in various forms on 4 places in altera_jtaguart. Unify all those and do the read and masking on a single place. The new helper altera_jtaguart_tx_space() uses FIELD_GET(), so we can drop ALTERA_JTAGUART_CONTROL_WSPACE_OFF now. Cc: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20220927111819.18516-3-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30tty: serial: use FIELD_GET() in lqasc_tx_ready()Jiri Slaby1-2/+2
FIELD_GET() can do the job smarter and more readable. We don't even need ASCFSTAT_TXFREEOFF. So switch to the former and remove the latter. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220927111819.18516-2-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30tty: serial: extend lqasc_tx_ready() to lqasc_console_putchar()Jiri Slaby1-6/+3
There is one more place where lqasc_tx_ready() can be used now: lqasc_console_putchar(). So replace the open-coded variant by the helper. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Jiri Slaby <jslaby@suse.cz> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20220927111819.18516-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30tty: serial: allow pxa.c to be COMPILE_TESTedJiri Slaby1-1/+1
There is no issue compiling pxa.c even in the SERIAL_8250=y case. So to cover it in the usual configurations, add "|| COMPILE_TEST" there. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Link: https://lore.kernel.org/r/20220927110528.12815-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30serial: stm32: Fix unused-variable warningRen Zhijie1-3/+3
If CONFIG_SERIAL_EARLYCON and CONFIG_OF are both not set, gcc warns about unused variable: drivers/tty/serial/stm32-usart.c:83:32: error: ‘stm32h7_info’ defined but not used [-Werror=unused-variable] static struct stm32_usart_info stm32h7_info = { ^~~~~~~~~~~~ drivers/tty/serial/stm32-usart.c:61:32: error: ‘stm32f7_info’ defined but not used [-Werror=unused-variable] static struct stm32_usart_info stm32f7_info = { ^~~~~~~~~~~~ drivers/tty/serial/stm32-usart.c:40:32: error: ‘stm32f4_info’ defined but not used [-Werror=unused-variable] static struct stm32_usart_info stm32f4_info = { ^~~~~~~~~~~~ cc1: all warnings being treated as errors Mark these variables as __maybe_unused to fix this. Fixes: c7039ce904c0 ("serial: stm32: make info structs static to avoid sparse warnings") Signed-off-by: Ren Zhijie <renzhijie2@huawei.com> Link: https://lore.kernel.org/r/20220926025826.44145-1-renzhijie2@huawei.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-30tty: serial: atmel: Add COMMON_CLK dependency to SERIAL_ATMELSergiu Moga1-0/+1
Now that the driver makes use of `__clk_is_enabled()` in order to know whether a `clk_disable_unprepare()` is needed or not on the GCLK, a new dependency has been introduced: COMMON_CLK. If this `CONFIG_COMMON_CLK` is not enabled, whatever config may have this driver enabled without COMMON_CLK then an undefined reference to `__clk_is_enabled()` will be issued by the linker. Thus, make sure that, unless `CONFIG_COMMON_CLK` is enabled, this driver is not compiled. Fixes: 5e3ce1f26129 ("tty: serial: atmel: Make the driver aware of the existence of GCLK") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com> Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com> Link: https://lore.kernel.org/r/20220926143244.485578-1-sergiu.moga@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-27Merge branch 'master' into i2c/for-mergewindowWolfram Sang5-9/+10
2022-09-25serial: 8250: Fix restoring termios speed after suspendPali Rohár1-1/+6
Since commit edc6afc54968 ("tty: switch to ktermios and new framework") termios speed is no longer stored only in c_cflag member but also in new additional c_ispeed and c_ospeed members. If BOTHER flag is set in c_cflag then termios speed is stored only in these new members. Since commit 027b57170bf8 ("serial: core: Fix initializing and restoring termios speed") termios speed is available also in struct console. So properly restore also c_ispeed and c_ospeed members after suspend to fix restoring termios speed which is not represented by Bnnn constant. Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Signed-off-by: Pali Rohár <pali@kernel.org> Link: https://lore.kernel.org/r/20220924104324.4035-1-pali@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-25serial: Deassert Transmit Enable on probe in driver-specific wayLukas Wunner6-41/+37
When a UART port is newly registered, uart_configure_port() seeks to deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl. However a number of UART drivers interpret a set RTS bit as *assertion* instead of deassertion: Affected drivers include those using serial8250_em485_config() (except 8250_bcm2835aux.c) and some using mctrl_gpio (e.g. imx.c). Since the interpretation of the RTS bit is driver-specific, it is not suitable as a means to centrally deassert Transmit Enable in the serial core. Instead, the serial core must call on drivers to deassert it in their driver-specific way. One way to achieve that is to call ->rs485_config(). It implicitly deasserts Transmit Enable. So amend uart_configure_port() and uart_resume_port() to invoke uart_rs485_config(). That allows removing calls to uart_rs485_config() from drivers' ->probe() hooks and declaring the function static. Skip any invocation of ->set_mctrl() if RS485 is enabled. RS485 has no hardware flow control, so the modem control lines are irrelevant and need not be touched. When leaving RS485 mode, reset the modem control lines to the state stored in port->mctrl. That way, UARTs which are muxed between RS485 and RS232 transceivers drive the lines correctly when switched to RS232. (serial8250_do_startup() historically raises the OUT1 modem signal because otherwise interrupts are not signaled on ancient PC UARTs, but I believe that no longer applies to modern, RS485-capable UARTs and is thus safe to be skipped.) imx.c modifies port->mctrl whenever Transmit Enable is asserted and deasserted. Stop it from doing that so port->mctrl reflects the RS232 line state. 8250_omap.c deasserts Transmit Enable on ->runtime_resume() by calling ->set_mctrl(). Because that is now a no-op in RS485 mode, amend the function to call serial8250_em485_stop_tx(). fsl_lpuart.c retrieves and applies the RS485 device tree properties after registering the UART port. Because applying now happens on registration in uart_configure_port(), move retrieval of the properties ahead of uart_add_one_port(). Link: https://lore.kernel.org/all/20220329085050.311408-1-matthias.schiffer@ew.tq-group.com/ Link: https://lore.kernel.org/all/8f538a8903795f22f9acc94a9a31b03c9c4ccacb.camel@ginzinger.com/ Fixes: d3b3404df318 ("serial: Fix incorrect rs485 polarity on uart open") Cc: stable@vger.kernel.org # v4.14+ Reported-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reported-by: Roosen Henri <Henri.Roosen@ginzinger.com> Tested-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663863805.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-25serial: 8250_dma: Convert to use uart_xmit_advance()Andy Shevchenko1-3/+1
uart_xmit_advance() provides a common way on how to advance the Tx queue. Use it for the sake of unification and robustness. Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20220909091102.58941-1-andriy.shevchenko@linux.intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>