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2024-01-18Merge tag 'tty-6.8-rc1' of ↵Linus Torvalds80-914/+1028
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial updates from Greg KH: "Here is the big set of tty and serial driver changes for 6.8-rc1. As usual, Jiri has a bunch of refactoring and cleanups for the tty core and drivers in here, along with the usual set of rs485 updates (someday this might work properly...) Along with those, in here are changes for: - sc16is7xx serial driver updates - platform driver removal api updates - amba-pl011 driver updates - tty driver binding updates - other small tty/serial driver updates and changes All of these have been in linux-next for a while with no reported issues" * tag 'tty-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (197 commits) serial: sc16is7xx: refactor EFR lock serial: sc16is7xx: reorder code to remove prototype declarations serial: sc16is7xx: refactor FIFO access functions to increase commonality serial: sc16is7xx: drop unneeded MODULE_ALIAS serial: sc16is7xx: replace hardcoded divisor value with BIT() macro serial: sc16is7xx: add explicit return for some switch default cases serial: sc16is7xx: add macro for max number of UART ports serial: sc16is7xx: add driver name to struct uart_driver serial: sc16is7xx: use i2c_get_match_data() serial: sc16is7xx: use spi_get_device_match_data() serial: sc16is7xx: use DECLARE_BITMAP for sc16is7xx_lines bitfield serial: sc16is7xx: improve do/while loop in sc16is7xx_irq() serial: sc16is7xx: remove obsolete loop in sc16is7xx_port_irq() serial: sc16is7xx: set safe default SPI clock frequency serial: sc16is7xx: add check for unsupported SPI modes during probe serial: sc16is7xx: fix invalid sc16is7xx_lines bitfield in case of probe error serial: 8250_exar: Set missing rs485_supported flag serial: omap: do not override settings for RS485 support serial: core, imx: do not set RS485 enabled if it is not supported serial: core: make sure RS485 cannot be enabled when it is not supported ...
2024-01-11Merge tag 'soc-drivers-6.8' of ↵Linus Torvalds1-0/+16
git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc Pull SoC driver updates from Arnd Bergmann: "A new drivers/cache/ subsystem is added to contain drivers for abstracting cache flush methods on riscv and potentially others, as this is needed for handling non-coherent DMA but several SoCs require nonstandard hardware methods for it. op-tee gains support for asynchronous notification with FF-A, as well as support for a system thread for executing in secure world. The tee, reset, bus, memory and scmi subsystems have a couple of minor updates. Platform specific soc driver changes include: - Samsung Exynos gains driver support for Google GS101 (Tensor G1) across multiple subsystems - Qualcomm Snapdragon gains support for SM8650 and X1E along with added features for some other SoCs - Mediatek adds support for "Smart Voltage Scaling" on MT8186 and MT8195, and driver support for MT8188 along with some code refactoring. - Microchip Polarfire FPGA support for "Auto Update" of the FPGA bitstream - Apple M1 mailbox driver is rewritten into a SoC driver - minor updates on amlogic, mvebu, ti, zynq, imx, renesas and hisilicon" * tag 'soc-drivers-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (189 commits) memory: ti-emif-pm: Convert to platform remove callback returning void memory: ti-aemif: Convert to platform remove callback returning void memory: tegra210-emc: Convert to platform remove callback returning void memory: tegra186-emc: Convert to platform remove callback returning void memory: stm32-fmc2-ebi: Convert to platform remove callback returning void memory: exynos5422-dmc: Convert to platform remove callback returning void memory: renesas-rpc-if: Convert to platform remove callback returning void memory: omap-gpmc: Convert to platform remove callback returning void memory: mtk-smi: Convert to platform remove callback returning void memory: jz4780-nemc: Convert to platform remove callback returning void memory: fsl_ifc: Convert to platform remove callback returning void memory: fsl-corenet-cf: Convert to platform remove callback returning void memory: emif: Convert to platform remove callback returning void memory: brcmstb_memc: Convert to platform remove callback returning void memory: brcmstb_dpfe: Convert to platform remove callback returning void soc: qcom: llcc: Fix LLCC_TRP_ATTR2_CFGn offset firmware: qcom: qseecom: fix memory leaks in error paths dt-bindings: clock: google,gs101: rename CMU_TOP gate defines soc: qcom: llcc: Fix typo in kernel-doc dt-bindings: soc: qcom,aoss-qmp: document the X1E80100 Always-On Subsystem side channel ...
2024-01-04serial: sc16is7xx: refactor EFR lockHugo Villeneuve1-49/+57
Move common code for EFR lock/unlock of mutex into functions for code reuse and clarity. With the addition of old_lcr, move irda_mode within struct sc16is7xx_one to reduce memory usage: Before: /* size: 752, cachelines: 12, members: 10 */ After: /* size: 744, cachelines: 12, members: 10 */ Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-17-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: reorder code to remove prototype declarationsHugo Villeneuve1-39/+36
Move/reorder some functions to remove sc16is7xx_ier_set() and sc16is7xx_stop_tx() prototypes declarations. No functional change. sc16is7xx_ier_set() was introduced in commit cc4c1d05eb10 ("sc16is7xx: Properly resume TX after stop"). Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-16-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: refactor FIFO access functions to increase commonalityHugo Villeneuve1-8/+6
Simplify FIFO access functions by avoiding to declare a struct sc16is7xx_port *s variable within each function. This is mainly done to have more commonality between the max310x and sc16is7xx drivers. Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-15-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: drop unneeded MODULE_ALIASHugo Villeneuve1-2/+0
The MODULE_DEVICE_TABLE() already creates the proper aliases for the SPI driver. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-14-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: replace hardcoded divisor value with BIT() macroHugo Villeneuve1-1/+1
To better show why the limit is what it is, since we have only 16 bits for the divisor. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-13-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: add explicit return for some switch default casesHugo Villeneuve1-6/+2
Allows to simplify code by removing the break statement in the default switch/case in some functions. Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-12-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: add macro for max number of UART portsHugo Villeneuve1-4/+5
Add macro to hold the maximum number of UART ports per IC/device. Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-11-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: add driver name to struct uart_driverHugo Villeneuve1-0/+1
Make sure that the driver name is displayed instead of "unknown" when displaying the driver infos: Before: grep ttySC /proc/tty/drivers unknown /dev/ttySC 243 0-7 serial After: grep ttySC /proc/tty/drivers sc16is7xx /dev/ttySC 243 0-7 serial Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-10-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: use i2c_get_match_data()Hugo Villeneuve1-8/+3
Use preferred i2c_get_match_data() instead of device_get_match_data() and i2c_client_get_device_id() to get the driver match data. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-9-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: use spi_get_device_match_data()Hugo Villeneuve1-9/+3
Use preferred spi_get_device_match_data() instead of device_get_match_data() and spi_get_device_id() to get the driver match data. Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-8-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: use DECLARE_BITMAP for sc16is7xx_lines bitfieldHugo Villeneuve1-5/+5
Replace the explicit sc16is7xx_lines bitfield declaration with the generic macro DECLARE_BITMAP() to reserve just enough memory to contain all required bits. This also improves code self-documentation by showing the maximum number of bits required. This conversion now makes sc16is7xx_lines an array, so drop the "&" before sc16is7xx_lines in all bit access functions. Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-7-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: improve do/while loop in sc16is7xx_irq()Hugo Villeneuve1-5/+6
Simplify and improve readability by replacing while(1) loop with do {} while, and by using the keep_polling variable as the exit condition, making it more explicit. Fixes: 834449872105 ("sc16is7xx: Fix for multi-channel stall") Cc: <stable@vger.kernel.org> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-6-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: remove obsolete loop in sc16is7xx_port_irq()Hugo Villeneuve1-44/+41
Commit 834449872105 ("sc16is7xx: Fix for multi-channel stall") changed sc16is7xx_port_irq() from looping multiple times when there was still interrupts to serve. It simply changed the do {} while(1) loop to a do {} while(0) loop, which makes the loop itself now obsolete. Clean the code by removing this obsolete do {} while(0) loop. Fixes: 834449872105 ("sc16is7xx: Fix for multi-channel stall") Cc: <stable@vger.kernel.org> Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-5-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: set safe default SPI clock frequencyHugo Villeneuve1-1/+2
15 MHz is supported only by 76x variants. If the SPI clock frequency is not specified, use a safe default clock value of 4 MHz that is supported by all variants. Also use HZ_PER_MHZ macro to improve readability. Fixes: 2c837a8a8f9f ("sc16is7xx: spi interface is added") Cc: <stable@vger.kernel.org> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-4-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: add check for unsupported SPI modes during probeHugo Villeneuve1-1/+4
The original comment is confusing because it implies that variants other than the SC16IS762 supports other SPI modes beside SPI_MODE_0. Extract from datasheet: The SC16IS762 differs from the SC16IS752 in that it supports SPI clock speeds up to 15 Mbit/s instead of the 4 Mbit/s supported by the SC16IS752... In all other aspects, the SC16IS762 is functionally and electrically the same as the SC16IS752. The same is also true of the SC16IS760 variant versus the SC16IS740 and SC16IS750 variants. For all variants, only SPI mode 0 is supported. Change comment and abort probing if the specified SPI mode is not SPI_MODE_0. Fixes: 2c837a8a8f9f ("sc16is7xx: spi interface is added") Cc: <stable@vger.kernel.org> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-3-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: sc16is7xx: fix invalid sc16is7xx_lines bitfield in case of probe errorHugo Villeneuve1-26/+18
If an error occurs during probing, the sc16is7xx_lines bitfield may be left in a state that doesn't represent the correct state of lines allocation. For example, in a system with two SC16 devices, if an error occurs only during probing of channel (port) B of the second device, sc16is7xx_lines final state will be 00001011b instead of the expected 00000011b. This is caused in part because of the "i--" in the for/loop located in the out_ports: error path. Fix this by checking the return value of uart_add_one_port() and set line allocation bit only if this was successful. This allows the refactor of the obfuscated for(i--...) loop in the error path, and properly call uart_remove_one_port() only when needed, and properly unset line allocation bits. Also use same mechanism in remove() when calling uart_remove_one_port(). Fixes: c64349722d14 ("sc16is7xx: support multiple devices") Cc: <stable@vger.kernel.org> Cc: Yury Norov <yury.norov@gmail.com> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231221231823.2327894-2-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: 8250_exar: Set missing rs485_supported flagLino Sanfilippo1-2/+3
The UART supports an auto-RTS mode in which the RTS pin is automatically activated during transmission. So mark this mode as being supported even if RTS is not controlled by the driver but the UART. Also the serial core expects now at least one of both modes rts-on-send or rts-after-send to be supported. This is since during sanitization unsupported flags are deleted from a RS485 configuration set by userspace. However if the configuration ends up with both flags unset, the core prints a warning since it considers such a configuration invalid (see uart_sanitize_serial_rs485()). Cc: <stable@vger.kernel.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-8-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: omap: do not override settings for RS485 supportLino Sanfilippo1-13/+14
The drivers RS485 support is deactivated if there is no RTS GPIO available. This is done by nullifying the ports rs485_supported struct. After that however the settings in serial_omap_rs485_supported are assigned to the same structure unconditionally, which results in an unintended reactivation of RS485 support. Fix this by moving the assignment to the beginning of serial_omap_probe_rs485() and thus before uart_get_rs485_mode() gets called. Also replace the assignment of rs485_config() to have the complete RS485 setup in one function. Fixes: e2752ae3cfc9 ("serial: omap: Disallow RS-485 if rts-gpio is not specified") Cc: <stable@vger.kernel.org> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240103061818.564-7-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core, imx: do not set RS485 enabled if it is not supportedLino Sanfilippo2-7/+3
If the imx driver cannot support RS485 it nullifies the ports rs485_supported structure. But it still calls uart_get_rs485_mode() which may set the RS485_ENABLED flag nevertheless. This may lead to an attempt to configure RS485 even if it is not supported when the flag is evaluated in uart_configure_port() at port startup. Avoid this by bailing out of uart_get_rs485_mode() if the RS485_ENABLED flag is not supported by the caller. With this fix a check for RTS availability is now obsolete in the imx driver, since it can not evaluate to true any more. So remove this check. Furthermore the explicit nullifcation of rs485_supported is not needed, since the memory has already been set to zeros at allocation. So remove this, too. Fixes: 00d7a00e2a6f ("serial: imx: Fill in rs485_supported") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Link: https://lore.kernel.org/r/20240103061818.564-6-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: make sure RS485 cannot be enabled when it is not supportedLino Sanfilippo1-1/+1
Some uart drivers specify a rs485_config() function and then decide later to disable RS485 support for some reason (e.g. imx and ar933). In these cases userspace may be able to activate RS485 via TIOCSRS485 nevertheless, since in uart_set_rs485_config() an existing rs485_config() function indicates that RS485 is supported. Make sure that this is not longer possible by checking the uarts rs485_supported.flags instead and bailing out if SER_RS485_ENABLED is not set. Furthermore instead of returning an empty structure return -ENOTTY if the RS485 configuration is requested via TIOCGRS485 but RS485 is not supported. This has a small impact on userspace visibility but it is consistent with the -ENOTTY error for TIOCGRS485. Fixes: e849145e1fdd ("serial: ar933x: Fill in rs485_supported") Fixes: 55e18c6b6d42 ("serial: imx: Remove serial_rs485 sanitization") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-5-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: fix sanitizing check for RTS settingsLino Sanfilippo1-10/+18
Among other things uart_sanitize_serial_rs485() tests the sanity of the RTS settings in a RS485 configuration that has been passed by userspace. If RTS-on-send and RTS-after-send are both set or unset the configuration is adjusted and RTS-after-send is disabled and RTS-on-send enabled. This however makes only sense if both RTS modes are actually supported by the driver. With commit be2e2cb1d281 ("serial: Sanitize rs485_struct") the code does take the driver support into account but only checks if one of both RTS modes are supported. This may lead to the errorneous result of RTS-on-send being set even if only RTS-after-send is supported. Fix this by changing the implemented logic: First clear all unsupported flags in the RS485 configuration, then adjust an invalid RTS setting by taking into account which RTS mode is supported. Cc: <stable@vger.kernel.org> Fixes: be2e2cb1d281 ("serial: Sanitize rs485_struct") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-4-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: set missing supported flag for RX during TX GPIOLino Sanfilippo1-0/+2
If the RS485 feature RX-during-TX is supported by means of a GPIO set the according supported flag. Otherwise setting this feature from userspace may not be possible, since in uart_sanitize_serial_rs485() the passed RS485 configuration is matched against the supported features and unsupported settings are thereby removed and thus take no effect. Cc: <stable@vger.kernel.org> Fixes: 163f080eb717 ("serial: core: Add option to output RS485 RX_DURING_TX state via GPIO") Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-3-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: Do not hold the port lock when setting rx-during-tx GPIOLino Sanfilippo3-12/+26
Both the imx and stm32 driver set the rx-during-tx GPIO in rs485_config(). Since this function is called with the port lock held, this can be a problem in case that setting the GPIO line can sleep (e.g. if a GPIO expander is used which is connected via SPI or I2C). Avoid this issue by moving the GPIO setting outside of the port lock into the serial core and thus making it a generic feature. Also with commit c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") the SER_RS485_RX_DURING_TX flag is only set if a rx-during-tx GPIO is _not_ available, which is wrong. Fix this, too. Furthermore reset old GPIO settings in case that changing the RS485 configuration failed. Fixes: c54d48543689 ("serial: stm32: Add support for rs485 RX_DURING_TX output GPIO") Fixes: ca530cfa968c ("serial: imx: Add support for RS485 RX_DURING_TX output GPIO") Cc: Shawn Guo <shawnguo@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Lino Sanfilippo <l.sanfilippo@kunbus.com> Link: https://lore.kernel.org/r/20240103061818.564-2-l.sanfilippo@kunbus.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: 8250_bcm2835aux: Restore clock error handlingStefan Wahren1-0/+2
The commit fcc446c8aa63 ("serial: 8250_bcm2835aux: Add ACPI support") dropped the error handling for clock acquiring. But even an optional clock needs this. Fixes: fcc446c8aa63 ("serial: 8250_bcm2835aux: Add ACPI support") Cc: stable <stable@kernel.org> Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> Link: https://lore.kernel.org/r/20231220114334.4712-1-wahrenst@gmx.net Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-048250: microchip: pci1xxxx: Add Burst mode reception support in uart driver ↵Rengarajan S1-2/+121
for writing into FIFO In PCI1XXXX C0 endpoint, support for Burst mode is added. pci1xxxx_handle_irq checks the burst status and based on that incoming characters are received in DWORDs, RX handling is done in pci1xxxx_rx_burst. While reading the burst status the RX error is checked and the corresponding error statistics are updated. Signed-off-by: Rengarajan S <rengarajan.s@microchip.com> Link: https://lore.kernel.org/r/20231215151123.41812-4-rengarajan.s@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-048250: microchip: pci1xxxx: Add Syslock support for reading UART system registersRengarajan S1-0/+63
Different Host drivers can attempt to access system registers simultaneously from different memory spaces at the same time. The syslock mechanism provides a safe option for reading UART system registers and prevents conflicts by serializing access. Added three padding bytes in the structure for memory alignment. Signed-off-by: Rengarajan S <rengarajan.s@microchip.com> Link: https://lore.kernel.org/r/20231215151123.41812-3-rengarajan.s@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-048250: microchip: pci1xxxx: Rearranging the structure declarationsRengarajan S1-13/+13
Structure declarations in 8250_pci1xxxx.c have been moved above the functions for code readability. Signed-off-by: Rengarajan S <rengarajan.s@microchip.com> Link: https://lore.kernel.org/r/20231215151123.41812-2-rengarajan.s@microchip.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: 8250_lpss: copy dma_param using devm_kmemdup()Raag Jadav1-5/+2
Use devm_kmemdup() helper to copy dma_param instead of doing it manually. Signed-off-by: Raag Jadav <raag.jadav@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Link: https://lore.kernel.org/r/20240102055006.27256-1-raag.jadav@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04tty: serial: 8250: Set RS232 as default for Moxa PCIe board initializationCrescent CY Hsieh1-3/+4
After switching the serial interface of the Moxa RS232 PCIe boards, it fails to reset to RS232 when attempting to reload 8250_pci driver. This patch set RS232 as the default setting during the initialization of Moxa PCIe board. Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> Link: https://lore.kernel.org/r/20240102053133.9795-1-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: 8250_dw: Do not bailout on UCV read returning zeroVamshi Gajjela1-9/+3
Designware UART has optional feature FIFO_MODE to implement FIFO. Encoding FIFO capabilities through Component Parameter Register CPR is optional and it can be enabled using parameter UART_ADD_ENCODED_PARAMS. Driver can exercise fifo capabilities by decoding CPR if implemented or from cpr_val provided from the dw8250_platform_data otherwise. dw8250_setup_port() checks for CPR or cpr_val to determine FIFO size only when Component Version (UCV) is non-zero. Bailing out early on UCV read returning zero will leave fifosize as zero and !UART_CAP_FIFO, hence prevent early return and continue to process CPR or cpr_val for the driver to utilize FIFO. Non-zero UCV implies ADDITIONAL_FEATURES=1, preventing early return will not be an overhead here. Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231231182951.877805-1-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: imx: Ensure that imx_uart_rs485_config() is called with enabled clockChristoph Niedermaier1-11/+12
There are register accesses in the function imx_uart_rs485_config(). The clock must be enabled for these accesses. This was ensured by calling it via the function uart_rs485_config() in the probe() function within the range where the clock is enabled. With the commit 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way") it was removed from the probe() function and is now only called through the function uart_add_one_port() which is located at the end of the probe() function. But the clock is already switched off in this area. To ensure that the clock is enabled during register access, move the disabling of the clock to the very end of the probe() function. To avoid leaking enabled clocks on error also add an error path for exiting with disabling the clock. Fixes: 7c7f9bc986e6 ("serial: Deassert Transmit Enable on probe in driver-specific way") Cc: stable <stable@kernel.org> Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Reviewed-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/20231226113647.39376-1-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: apbuart: fix console prompt on qemuSam Ravnborg1-1/+1
When using a leon kernel with qemu there where no console prompt. The root cause is the handling of the fifo size in the tx part of the apbuart driver. The qemu uart driver only have a very rudimentary status handling and do not report the number of chars queued in the tx fifo in the status register. So the driver ends up with a fifo size of 1. In the tx path the fifo size is divided by 2 - resulting in a fifo size of zero. The original implementation would always try to send one char, but after the introduction of uart_port_tx_limited() the fifo size is respected even for the first char. There seems to be no good reason to divide the fifo size with two - so remove this. It looks like something copied from the original amba driver. With qemu we now have a minimum fifo size of one char, so we show the prompt. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Fixes: d11cc8c3c4b6 ("tty: serial: use uart_port_tx_limited()") Cc: Andreas Larsson <andreas@gaisler.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: <linux-serial@vger.kernel.org> Cc: <sparclinux@vger.kernel.org> Link: https://lore.kernel.org/r/20231226121607.GA2622970@ravnborg.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04tty: serial: kgdboc: Fix 8250_* kgdb over serialMichael Trimarchi1-1/+2
Check if port type is not PORT_UNKNOWN during poll_init. The kgdboc calls the tty_find_polling_driver that check if the serial is able to use poll_init. The poll_init calls the uart uart_poll_init that try to configure the uart with the selected boot parameters. The uart must be ready before setting parameters. Seems that PORT_UNKNOWN is already used by other functions in serial_core to detect uart status, so use the same to avoid to use it in invalid state. The crash happen for instance in am62x architecture where the 8250 register the platform driver after the 8250 core is initialized. Follow the report crash coming from KGDB Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt This section of the code is too early because in this case the omap serial is not probed Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt Thread 2 received signal SIGSEGV, Segmentation fault. [Switching to Thread 1] _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 584 __raw_writeb(value, PCI_IOBASE + addr); (gdb) bt 0 _outb (addr=<optimized out>, value=<optimized out>) at ./include/asm-generic/io.h:584 1 logic_outb (value=0 '\000', addr=18446739675637874689) at lib/logic_pio.c:299 2 0xffff80008082dfcc in io_serial_out (p=0x0, offset=16760830, value=0) at drivers/tty/serial/8250/8250_port.c:416 3 0xffff80008082fe34 in serial_port_out (value=<optimized out>, offset=<optimized out>, up=<optimized out>) at ./include/linux/serial_core.h:677 4 serial8250_do_set_termios (port=0xffff8000828ee940 <serial8250_ports+1568>, termios=0xffff80008292b93c, old=0x0) at drivers/tty/serial/8250/8250_port.c:2860 5 0xffff800080830064 in serial8250_set_termios (port=0xfffffbfffe800000, termios=0xffbffe, old=0x0) at drivers/tty/serial/8250/8250_port.c:2912 6 0xffff80008082571c in uart_set_options (port=0xffff8000828ee940 <serial8250_ports+1568>, co=0x0, baud=115200, parity=110, bits=8, flow=110) at drivers/tty/serial/serial_core.c:2285 7 0xffff800080828434 in uart_poll_init (driver=0xfffffbfffe800000, line=16760830, options=0xffff8000828f7506 <config+6> "115200n8") at drivers/tty/serial/serial_core.c:2656 8 0xffff800080801690 in tty_find_polling_driver (name=0xffff8000828f7500 <config> "ttyS2,115200n8", line=0xffff80008292ba90) at drivers/tty/tty_io.c:410 9 0xffff80008086c0b0 in configure_kgdboc () at drivers/tty/serial/kgdboc.c:194 10 0xffff80008086c1ec in kgdboc_probe (pdev=0xfffffbfffe800000) at drivers/tty/serial/kgdboc.c:249 11 0xffff8000808b399c in platform_probe (_dev=0xffff000000ebb810) at drivers/base/platform.c:1404 12 0xffff8000808b0b44 in call_driver_probe (drv=<optimized out>, dev=<optimized out>) at drivers/base/dd.c:579 13 really_probe (dev=0xffff000000ebb810, drv=0xffff80008277f138 <kgdboc_platform_driver+48>) at drivers/base/dd.c:658 14 0xffff8000808b0d2c in __driver_probe_device (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, dev=0xffff000000ebb810) at drivers/base/dd.c:800 15 0xffff8000808b0eb8 in driver_probe_device (drv=0xfffffbfffe800000, dev=0xffff000000ebb810) at drivers/base/dd.c:830 16 0xffff8000808b0ff4 in __device_attach_driver (drv=0xffff80008277f138 <kgdboc_platform_driver+48>, _data=0xffff80008292bc48) at drivers/base/dd.c:958 17 0xffff8000808ae970 in bus_for_each_drv (bus=0xfffffbfffe800000, start=0x0, data=0xffff80008292bc48, fn=0xffff8000808b0f3c <__device_attach_driver>) at drivers/base/bus.c:457 18 0xffff8000808b1408 in __device_attach (dev=0xffff000000ebb810, allow_async=true) at drivers/base/dd.c:1030 19 0xffff8000808b16d8 in device_initial_probe (dev=0xfffffbfffe800000) at drivers/base/dd.c:1079 20 0xffff8000808af9f4 in bus_probe_device (dev=0xffff000000ebb810) at drivers/base/bus.c:532 21 0xffff8000808ac77c in device_add (dev=0xfffffbfffe800000) at drivers/base/core.c:3625 22 0xffff8000808b3428 in platform_device_add (pdev=0xffff000000ebb800) at drivers/base/platform.c:716 23 0xffff800081b5dc0c in init_kgdboc () at drivers/tty/serial/kgdboc.c:292 24 0xffff800080014db0 in do_one_initcall (fn=0xffff800081b5dba4 <init_kgdboc>) at init/main.c:1236 25 0xffff800081b0114c in do_initcall_level (command_line=<optimized out>, level=<optimized out>) at init/main.c:1298 26 do_initcalls () at init/main.c:1314 27 do_basic_setup () at init/main.c:1333 28 kernel_init_freeable () at init/main.c:1551 29 0xffff8000810271ec in kernel_init (unused=0xfffffbfffe800000) at init/main.c:1441 30 0xffff800080015e80 in ret_from_fork () at arch/arm64/kernel/entry.S:857 Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com> Link: https://lore.kernel.org/r/20231224131200.266224-1-michael@amarulasolutions.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: imx: Correct clock error message in function probe()Christoph Niedermaier1-1/+1
Correct the clock error message by changing the clock name. Fixes: 1e512d45332b ("serial: imx: add error messages when .probe fails") Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231224093209.2612-1-cniedermaier@dh-electronics.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04tty/serial: altera_uart: use more informative labels in /proc/interruptsAntony Pavlov1-1/+1
Prior to this patch: ~# cat /proc/interrupts ... 40: 123 0 GIC-0 72 Level altera_uart 41: 9 0 GIC-0 73 Level altera_uart After this patch: ~# cat /proc/interrupts ... 40: 6 0 GIC-0 72 Level ff200100.fpga-uart0 41: 28 0 GIC-0 73 Level ff200200.fpga-uart1 Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com> Acked-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/r/20231217195601.236002-1-antonynpavlov@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04tty: serial: Add RS422 flag to struct serial_rs485Crescent CY Hsieh1-0/+6
Add "SER_RS485_MODE_RS422" flag to struct serial_rs485, so that serial port can switch interface into RS422 if supported by using ioctl command "TIOCSRS485". By treating RS422 as a mode of RS485, which means while enabling RS422 there are two flags need to be set (SER_RS485_ENABLED and SER_RS485_MODE_RS422), it would make things much easier. For example some places that checks for "SER_RS485_ENABLED" won't need to be rewritten. Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> Link: https://lore.kernel.org/r/20231201071554.258607-3-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-01-04serial: core: Clean up uart_update_timeout() functionVamshi Gajjela1-4/+3
Rename the variable size to temp and change its data type from unsigned int to u64 to avoid type casting in multiplication. Remove the intermediate variable frame_time and use temp instead to accommodate the nanoseconds(ns). port->frame_time is an unsigned int, therefore an explicit cast is used to improve readability. Having said this unsigned int is sufficinet to hold frame time duration in nanoseconds for all the standard baudrates. Consider 9600 baud, it takes 1/9600 seconds for one bit, for a total of 10 bits (start, 8-bit data, stop) 10/9600=1.04 ms for 1 byte transfer, frame_time here is 1041667ns. As baudrate increases frame_time decreases, say for 115200 baud it is 86806ns. To avoid costly 64-bit arithmetic we do not upconvert the type for variable frame_time as overflow happens for extremely low baudrates which are impractical and are not used in real-world applications. Signed-off-by: Vamshi Gajjela <vamshigajjela@google.com> Link: https://lore.kernel.org/r/20231109063417.3971005-3-vamshigajjela@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: 8250: Set RS422 interface by default to fix Moxa RS422/RS485 ↵Crescent CY Hsieh1-1/+57
PCIe boards MOXA PCIe RS422/RS485 boards will not function by default because of the initial default serial interface of all MOXA PCIe boards is set to RS232. This patch fixes the problem above by setting the initial default serial interface to RS422 for those MOXA RS422/RS485 PCIe boards. Signed-off-by: Crescent CY Hsieh <crescentcy.hsieh@moxa.com> Reviewed-by: Jiri Slaby <jirislaby@kernel.org> Link: https://lore.kernel.org/r/20231214060234.6147-1-crescentcy.hsieh@moxa.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: factor QDF2400 SoC erratum 44 out of probeThéo Lebrun1-7/+18
On this platform, different vendor data is used. That requires a compile-time check as we access (1) a global boolean & (2) our local vendor data. Both symbols are accessible only when CONFIG_ACPI_SPCR_TABLE is enabled. Factor the vendor data overriding to a separate function that is empty when CONFIG_ACPI_SPCR_TABLE is not defined. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-8-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: unindent pl011_console_get_options function bodyThéo Lebrun1-22/+21
The whole function body is encapsulated inside an if-condition. Reverse the if logic and early return to remove one indentation level. Also turn two nested ifs into a single one at the end of the function. Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-7-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: fix miscellaneous checkpatch warningsThéo Lebrun1-7/+6
Fix the following messages from checkpatch: $ ./scripts/checkpatch.pl --strict --file \ drivers/tty/serial/amba-pl011.c ERROR: do not initialise statics to false WARNING: Possible unnecessary 'out of memory' message WARNING: Prefer 'unsigned int' to bare use of 'unsigned' WARNING: Prefer [subsystem eg: netdev]_info([subsystem]dev, ... then dev_info(dev, ... then pr_info(... to CHECK: Prefer using the BIT macro Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-6-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: fix formatting of conditionsThéo Lebrun1-12/+14
Fix the following checkpatch warnings & checks: $ ./scripts/checkpatch.pl --strict --file \ drivers/tty/serial/amba-pl011.c CHECK: Unbalanced braces around else statement CHECK: Unnecessary parentheses around '[...]' CHECK: braces {} should be used on all arms of this statement CHECK: Comparison to NULL could be written "[...]" WARNING: Comparisons should place the constant on the right side of the test Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-5-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: avoid quoted string split across linesThéo Lebrun1-8/+8
Remove all instances of quoted strings split across lines. Fix four checkpatch warnings: $ ./scripts/checkpatch.pl --strict --file \ drivers/tty/serial/amba-pl011.c WARNING: quoted string split across lines [...] Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-4-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: replace TIOCMBIT macros by static functionsThéo Lebrun1-21/+24
The driver uses two TIOCMBIT macros inside pl011_{get,set}_mctrl to simplify the logic. Those look scary to checkpatch because they contain ifs without do-while loops. Avoid the macros by creating small equivalent static functions; that lets the compiler do its type checking & avoids checkpatch errors. For the second instance __assign_bit is not usable because it deals with unsigned long pointers whereas we have an unsigned int in pl011_set_mctrl. This addresses the following checkpatch warnings: $ ./scripts/checkpatch.pl --strict --file \ drivers/tty/serial/amba-pl011.c ERROR: Macros starting with if should be enclosed by a do - while loop to avoid possible if/else logic defects CHECK: Macro argument 'uartbit' may be better as '(uartbit)' to avoid precedence issues ERROR: Macros starting with if should be enclosed by a do - while loop to avoid possible if/else logic defects CHECK: Macro argument 'tiocmbit' may be better as '(tiocmbit)' to avoid precedence issues Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-3-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15tty: serial: amba-pl011: fix whitespace formattingThéo Lebrun1-52/+45
Follow recommandations from: $ ./scripts/checkpatch.pl --strict --file \ drivers/tty/serial/amba-pl011.c We fix 5 warnings and 48 checks, all related to whitespace. Culprits are: CHECK: Alignment should match open parenthesis CHECK: Blank lines aren't necessary after an open brace '{' CHECK: Lines should not end with a '(' CHECK: Please don't use multiple blank lines CHECK: Please use a blank line after function/struct/union/enum declarations CHECK: spaces preferred around that '/' (ctx:VxV) CHECK: spaces preferred around that '|' (ctx:VxV) WARNING: Missing a blank line after declarations WARNING: please, no spaces at the start of a line Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com> Link: https://lore.kernel.org/r/20231207-mbly-uart-v6-2-e384afa5e78c@bootlin.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15serial: 8250-fsl: Only do the break workaround if IIR signals RLSIUwe Kleine-König1-1/+2
It can happen that while a break is received the transmitter gets empty and IIR signals a Transmitter holding register empty (THRI) event. In this case it's too early for the break workaround. Still doing it then results in the THRI event not being rereported which makes the driver miss that and e.g. for RS485 half-duplex communication it fails to switch back to RX mode. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20231213174312.2341013-1-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15serial: ma35d1: Fix spelling mistake "ononsole" -> "console"Colin Ian King1-1/+1
There is a spelling mistake in a pr_warn message. Fix it. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Link: https://lore.kernel.org/r/20231208102331.3267192-1-colin.i.king@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15serial: sc16is7xx: fix unconditional activation of THRI interruptHugo Villeneuve1-5/+2
Commit cc4c1d05eb10 ("sc16is7xx: Properly resume TX after stop") changed behavior to unconditionnaly set the THRI interrupt in sc16is7xx_tx_proc(). For example when sending a 65 bytes message, and assuming the Tx FIFO is initially empty, sc16is7xx_handle_tx() will write the first 64 bytes of the message to the FIFO and sc16is7xx_tx_proc() will then activate THRI. When the THRI IRQ is fired, the driver will write the remaining byte of the message to the FIFO, and disable THRI by calling sc16is7xx_stop_tx(). When sending a 2 bytes message, sc16is7xx_handle_tx() will write the 2 bytes of the message to the FIFO and call sc16is7xx_stop_tx(), disabling THRI. After sc16is7xx_handle_tx() exits, control returns to sc16is7xx_tx_proc() which will unconditionally set THRI. When the THRI IRQ is fired, the driver simply acknowledges the interrupt and does nothing more, since all the data has already been written to the FIFO. This results in 2 register writes and 4 register reads all for nothing and taking precious cycles from the I2C/SPI bus. Fix this by enabling the THRI interrupt only when we fill the Tx FIFO to its maximum capacity and there are remaining bytes to send in the message. Fixes: cc4c1d05eb10 ("sc16is7xx: Properly resume TX after stop") Cc: <stable@vger.kernel.org> Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com> Link: https://lore.kernel.org/r/20231211171353.2901416-7-hugo@hugovil.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>