kernel/drivers/tty/serial/msm_serial.c, branch linux-6.9.y

serial: msm: Use uart_prepare_sysrq_char().

2024-03-02T21:06:21Z

The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT. The driver splits the locking function into two parts: local_irq_save() and uart_port_lock() and this breaks PREEMPT_RT. Delay handling sysrq until port lock is dropped. Remove the special case in the console write routine an always use the complete locking function. Cc: Bjorn Andersson Cc: Konrad Dybcio Cc: linux-arm-msm@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20240301215246.891055-6-bigeasy@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: msm: Use OPP table for DVFS support

2023-12-08T11:02:37Z

Parse the OPP table from the device tree and use dev_pm_opp_set_rate() instead of clk_set_rate() to allow making performance state votes specified in the OPP table (e.g. for power domains and interconnects). Without an OPP table in the device tree this will behave just as before this patch. Signed-off-by: Stephan Gerhold Link: https://lore.kernel.org/r/20231128-serial-msm-dvfs-v1-2-4f290d20a4be@kernkonzept.com Signed-off-by: Greg Kroah-Hartman

serial: msm: Convert to platform remove callback returning void

2023-11-23T19:12:33Z

The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is ignored (apart from emitting a warning) and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new(), which already returns void. Eventually after all drivers are converted, .remove_new() will be renamed to .remove(). Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König Link: https://lore.kernel.org/r/20231110152927.70601-27-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

serial: msm: Use port lock wrappers

2023-09-18T09:18:12Z

When a serial port is used for kernel console output, then all modifications to the UART registers which are done from other contexts, e.g. getty, termios, are interference points for the kernel console. So far this has been ignored and the printk output is based on the principle of hope. The rework of the console infrastructure which aims to support threaded and atomic consoles, requires to mark sections which modify the UART registers as unsafe. This allows the atomic write function to make informed decisions and eventually to restore operational state. It also allows to prevent the regular UART code from modifying UART registers while printk output is in progress. All modifications of UART registers are guarded by the UART port lock, which provides an obvious synchronization point with the console infrastructure. To avoid adding this functionality to all UART drivers, wrap the spin_[un]lock*() invocations for uart_port::lock into helper functions which just contain the spin_[un]lock*() invocations for now. In a subsequent step these helpers will gain the console synchronization mechanisms. Converted with coccinelle. No functional change. Signed-off-by: Thomas Gleixner Reviewed-by: Bjorn Andersson Signed-off-by: John Ogness Link: https://lore.kernel.org/r/20230914183831.587273-42-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman

serial: msm: add lock annotation to msm_set_baud_rate()

2023-01-19T14:53:09Z

msm_set_baud_rate() releases and re-acquires the port->lock, thus add lock annotation for Sparse static code checks. Signed-off-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20230109152212.343476-1-krzysztof.kozlowski@linaro.org Signed-off-by: Greg Kroah-Hartman

serial: Fix a typo ("ignorning")

2022-11-09T12:03:12Z

Fix the two instances of this typo present in the MSM and VT8500 serial drivers. Signed-off-by: Jonathan Neuschäfer Reviewed-by: Mukesh Ojha Acked-by: Konrad Dybcio Link: https://lore.kernel.org/r/20221104103719.2234098-1-j.neuschaefer@gmx.net Signed-off-by: Greg Kroah-Hartman

serial: msm: Use uart_xmit_advance()

2022-11-03T02:35:41Z

Take advantage of the new uart_xmit_advance() helper. Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20221019091151.6692-4-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: Make ->set_termios() old ktermios const

2022-08-30T12:22:35Z

There should be no reason to adjust old ktermios which is going to get discarded anyway. Reviewed-by: Andy Shevchenko Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220816115739.10928-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: msm: Rename UART_* defines to MSM_UART_*

2022-06-27T12:41:31Z

Using UART_* to name defines is a bit problematic. When trying to do unrelated cleanup which also involved tweaking header inclusion logic, caused UART_CSR from serial_reg.h to leak into msm's namespace which is also among msm defines. Thus, rename all UART_* ones to MSM_UART_* to eliminate possibility of collisions. Reviewed-by: Jiri Slaby Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220624205424.12686-3-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: msm: Convert container_of UART_TO_MSM to static inline

2022-06-27T12:41:31Z

Create static inline instead of define as it provides type safety and is safer wrt. macros expansion. Reviewed-by: Jiri Slaby Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20220624205424.12686-2-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman