kernel/linux.git/drivers/tty/serial/omap-serial.c, branch linux-4.4.y

serial: omap: Fix EFR write on RTS deassertion

2017-11-24T07:32:24+00:00

commit 2a71de2f7366fb1aec632116d0549ec56d6a3940 upstream. Commit 348f9bb31c56 ("serial: omap: Fix RTS handling") sought to enable auto RTS upon manual RTS assertion and disable it on deassertion. However it seems the latter was done incorrectly, it clears all bits in the Extended Features Register *except* auto RTS. Fixes: 348f9bb31c56 ("serial: omap: Fix RTS handling") Cc: Peter Hurley Signed-off-by: Lukas Wunner Signed-off-by: Greg Kroah-Hartman

serial: omap: suspend device on probe errors

2017-05-20T12:27:02+00:00

commit 77e6fe7fd2b7cba0bf2f2dc8cde51d7b9a35bf74 upstream. Make sure to actually suspend the device before returning after a failed (or deferred) probe. Note that autosuspend must be disabled before runtime pm is disabled in order to balance the usage count due to a negative autosuspend delay as well as to make the final put suspend the device synchronously. Fixes: 388bc2622680 ("omap-serial: Fix the error handling in the omap_serial probe") Cc: Shubhrajyoti D Signed-off-by: Johan Hovold Acked-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman

serial: omap: fix runtime-pm handling on unbind

2017-05-20T12:27:02+00:00

commit 099bd73dc17ed77aa8c98323e043613b6e8f54fc upstream. An unbalanced and misplaced synchronous put was used to suspend the device on driver unbind, something which with a likewise misplaced pm_runtime_disable leads to external aborts when an open port is being removed. Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa024010 ... [] (serial_omap_set_mctrl) from [] (uart_update_mctrl+0x50/0x60) [] (uart_update_mctrl) from [] (uart_shutdown+0xbc/0x138) [] (uart_shutdown) from [] (uart_hangup+0x94/0x190) [] (uart_hangup) from [] (__tty_hangup+0x404/0x41c) [] (__tty_hangup) from [] (tty_vhangup+0x1c/0x20) [] (tty_vhangup) from [] (uart_remove_one_port+0xec/0x260) [] (uart_remove_one_port) from [] (serial_omap_remove+0x40/0x60) [] (serial_omap_remove) from [] (platform_drv_remove+0x34/0x4c) Fix this up by resuming the device before deregistering the port and by suspending and disabling runtime pm only after the port has been removed. Also make sure to disable autosuspend before disabling runtime pm so that the usage count is balanced and device actually suspended before returning. Note that due to a negative autosuspend delay being set in probe, the unbalanced put would actually suspend the device on first driver unbind, while rebinding and again unbinding would result in a negative power.usage_count. Fixes: 7e9c8e7dbf3b ("serial: omap: make sure to suspend device before remove") Cc: Felipe Balbi Cc: Santosh Shilimkar Signed-off-by: Johan Hovold Acked-by: Tony Lindgren Signed-off-by: Greg Kroah-Hartman

serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485)

2016-02-25T20:01:14+00:00

commit 308bbc9ab838d0ace0298268c7970ba9513e2c65 upstream. The omap-serial driver emulates RS485 delays using software timers, but neglects to clamp the input values from the unprivileged ioctl(TIOCSRS485). Because the software implementation busy-waits, malicious userspace could stall the cpu for ~49 days. Clamp the input values to < 100ms. Fixes: 4a0ac0f55b18 ("OMAP: add RS485 support") Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: omap: remove warnings about unused functions

2015-10-04T18:14:26+00:00

They're used by only if CONFIG_PM is enabled, so enclose them with proper ifdefs. Removes these warnings: drivers/tty/serial/omap-serial.c:202:12: warning: 'serial_omap_get_context_loss_count' defined but not used [-Wunused-function] drivers/tty/serial/omap-serial.c:213:13: warning: 'serial_omap_enable_wakeup' defined but not used [-Wunused-function] Signed-off-by: Guido Martínez Signed-off-by: Ezequiel Garcia Signed-off-by: Greg Kroah-Hartman

serial: omap: Switch wake-up interrupt to generic wakeirq

2015-06-10T06:35:00+00:00

We can now use generic wakeirq handling and remove the custom handling for the wake-up interrupts. Acked-by: Greg Kroah-Hartman Signed-off-by: Tony Lindgren

serial: omap: Fix error handling in probe

2015-05-08T12:20:50+00:00

There is pm_qos_add_request() being executed on serial_omap_probe(), which stores "&up->pm_qos_request" from omap-serial driver to "pm_qos_array[PM_QOS_CPU_DMA_LATENCY]->constraints". If serial_omap_probe() fails after pm_qos_add_request() (e.g. on uart_add_one_port() call), pm_qos_array still keeping pm_qos_request struct from omap-serial driver, which is not valid anymore (since driver failed). This leads further to kernel crash on pm_qos_update_target(), executing from some completely different driver. We were observing this while trying to run audio playback while having one of omap-serial driver instances failed on uart_add_one_port() call: Unable to handle kernel paging request at virtual address fffffffc Backtrace: (plist_add) from (pm_qos_update_target) (pm_qos_update_target) from (pm_qos_add_request) (pm_qos_add_request) from (snd_pcm_hw_params) (snd_pcm_hw_params) from (snd_pcm_common_ioctl1) (snd_pcm_common_ioctl1) from (snd_pcm_playback_ioctl1) (snd_pcm_playback_ioctl1) from (snd_pcm_playback_ioctl) (snd_pcm_playback_ioctl) from (do_vfs_ioctl) (do_vfs_ioctl) from (SyS_ioctl) (SyS_ioctl) from (ret_fast_syscall) This patch adds pm_qos_remove_request() on fail path in serial_omap_probe() in order to fix this issue. While at it, free the wakeup settings on fail path as well, just like it's done in serial_omap_remove(). Signed-off-by: Semen Protsenko Signed-off-by: Greg Kroah-Hartman

tty/serial: omap: fix !wakeirq message

2015-03-26T21:38:36+00:00

When wakeirq is not used/enabled, "no wakeirq for uart0" is output for all TTY as the log message is generated before the port line is initialized. [ 0.802656] Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled [ 0.811700] omap_uart 44e09000.serial: no wakeirq for uart0 [ 0.812379] 44e09000.serial: ttyO0 at MMIO 0x44e09000 (irq = 88, base_baud = 3000000) is a OMAP UART0 [ 1.503622] console [ttyO0] enabled [ 1.509836] omap_uart 48022000.serial: no wakeirq for uart0 [ 1.516118] 48022000.serial: ttyO1 at MMIO 0x48022000 (irq = 89, base_baud = 3000000) is a OMAP UART1 [ 1.527711] omap_uart 48024000.serial: no wakeirq for uart0 [ 1.533881] 48024000.serial: ttyO2 at MMIO 0x48024000 (irq = 90, base_baud = 3000000) is a OMAP UART2 [ 1.545324] omap_uart 481a6000.serial: no wakeirq for uart0 [ 1.551410] 481a6000.serial: ttyO3 at MMIO 0x481a6000 (irq = 60, base_baud = 3000000) is a OMAP UART3 [ 1.562946] omap_uart 481a8000.serial: no wakeirq for uart0 [ 1.569036] 481a8000.serial: ttyO4 at MMIO 0x481a8000 (irq = 61, base_baud = 3000000) is a OMAP UART4 Fix by moving wakeirq initialization, check, and dev_info() call to after port line initialization and validation. Signed-off-by: Doug Kehn Signed-off-by: Greg Kroah-Hartman

serial: omap: Fix RTS handling

2015-02-02T18:11:28+00:00

The OMAP UART ignores MCR[1] (ie., RTS) when in autoRTS mode. This makes it impossible for either the serial core or userspace to manually flow control the sender. Disable autoRTS mode when RTS is lowered and restore the previous mode when RTS is raised. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman

serial: core: Rework hw-assisted flow control support

2015-02-02T18:11:28+00:00

hw-assisted flow control support was added to the serial core in v3.8 with commits, dba05832cbe4f ("SERIAL: core: add hardware assisted h/w flow control support") 2cbacafd7af0f ("SERIAL: core: add hardware assisted s/w flow control support") 9aba8d5b01119 ("SERIAL: core: add throttle/unthrottle callbacks for hardware assisted flow control") Since then, additional requirements for serial core support have arisen. Specifically, 1. Separate tx and rx flow control settings for UARTs which only support tx flow control (ie., autoCTS). 2. Disable sw-assisted CTS flow control in autoCTS mode 3. Support for RTS flow control by serial core and userspace in autoRTS mode Distinguish mode from capability; introduce UPSTAT_AUTORTS, UPSTAT_AUTOCTS and UPSTAT_AUTOXOFF which, when set by the uart driver, enable serial core support for hw-assisted rx, hw-assisted tx and hw-assisted in-band/IXOFF rx flow control, respectively. [Note: hw-assisted in-band/IXON tx flow control does not require serial core support/intervention and can be enabled by the uart driver when required.] These modes must be set/reset in the driver's set_termios() method, based on termios settings, and thus can be safely queried in any context in which one of the port lock, port mutex or termios rwsem are held. Set these modes in the 2 in-tree drivers, omap-serial and 8250_omap, which currently use UPF_HARD_FLOW/UPF_SOFT_FLOW support. Retain UPF_HARD_FLOW and UPF_SOFT_FLOW as capabilities; re-define UPF_HARD_FLOW as both UPF_AUTO_RTS and UPF_AUTO_CTS to allow for distinct and separate rx and tx flow control capabilities. Disable sw-assisted CTS flow control when UPSTAT_AUTOCTS is enabled. Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman