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

serial: sh-sci: protect invalidating RXDMA on shutdown

2024-06-12T09:39:21Z

[ Upstream commit aae20f6e34cd0cbd67a1d0e5877561c40109a81b ] The to-be-fixed commit removed locking when invalidating the DMA RX descriptors on shutdown. It overlooked that there is still a rx_timer running which may still access the protected data. So, re-add the locking. Reported-by: Dirk Behme Closes: https://lore.kernel.org/r/ee6c9e16-9f29-450e-81da-4a8dceaa8fc7@de.bosch.com Fixes: 2c4ee23530ff ("serial: sh-sci: Postpone DMA release when falling back to PIO") Signed-off-by: Wolfram Sang Link: https://lore.kernel.org/r/20240506114016.30498-7-wsa+renesas@sang-engineering.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: sh-sci: Call sci_serial_{in,out}() directly

2024-03-05T13:37:32Z

Unlike the 8250 serial driver complex, the sh-sci driver uses only a single pair of functions to read and write serial port registers. Hence there is no need to incur the overhead of calling them through indirection, like the serial_port_{in,out}() wrappers do. Replace all calls to these wrappers by direct calls to sci_serial_{in,out}(). Remove the setup of the uart_port.serial_{in,out}() callbacks. After removal of all calls to serial_port_{in,out}() in the sh-sci driver, the only remaining user is uart_xchar_out(), which the sh-sci driver does not use. Signed-off-by: Geert Uytterhoeven Acked-by: John Paul Adrian Glaubitz Link: https://lore.kernel.org/r/51e79d601cb9d9d63822d3773d3cf05a96868612.1709548811.git.geert+renesas@glider.be Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: convert not to use dma_request_slave_channel()

2023-11-23T19:33:03Z

dma_request_slave_channel() is deprecated. dma_request_chan() should be used directly instead. Switch to the preferred function and update the error handling accordingly. Signed-off-by: Christophe JAILLET Link: https://lore.kernel.org/r/d6773b9bd88dbbbea06bc6d5cd59aa117b1ee2ee.1700416841.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Convert to platform remove callback returning void

2023-11-23T19:12:34Z

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 Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20231110152927.70601-39-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman

serial: sh-sci: Use port lock wrappers

2023-09-18T09:18:15Z

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 Signed-off-by: John Ogness Link: https://lore.kernel.org/r/20230914183831.587273-61-john.ogness@linutronix.de Signed-off-by: Greg Kroah-Hartman

Merge 6.5-rc4 into tty-next

2023-07-31T07:39:56Z

We need the serial/tty fixes in here as well for testing and future development. Signed-off-by: Greg Kroah-Hartman

tty: serial: sh-sci: Fix sleeping in atomic context

2023-07-25T18:30:20Z

Fix sleeping in atomic context warning as reported by the Smatch static checker tool by replacing disable_irq->disable_irq_nosync. Reported by: Dan Carpenter Fixes: 8749061be196 ("tty: serial: sh-sci: Add RZ/G2L SCIFA DMA tx support") Cc: stable@kernel.org Signed-off-by: Biju Das Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230704154818.406913-1-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

tty: Explicitly include correct DT includes

2023-07-25T18:19:05Z

The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring Acked-by: Uwe Kleine-König # for imx Link: https://lore.kernel.org/r/20230724205440.767071-1-robh@kernel.org Signed-off-by: Greg Kroah-Hartman

tty: serial: sh-sci: Fix end of transmission on SCI

2023-04-20T11:47:33Z

We need to set TE to "0" (i.e., disable serial transmission) to get the expected behavior of the end of serial transmission. Signed-off-by: Biju Das Link: https://lore.kernel.org/r/20230412145053.114847-6-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman

tty: serial: sh-sci: Add support for tx end interrupt handling

2023-04-20T11:47:33Z

As per the RZ/G2L users hardware manual (Rev.1.20 Sep, 2022), section 23.3.7 Serial Data Transmission (Asynchronous Mode), it is mentioned that, set the SCR.TIE bit to 0 and SCR.TEIE bit to 1, after the last data to be transmitted are written to the TDR. This will generate tx end interrupt and in the handler set SCR.TE and SCR.TEIE to 0. Signed-off-by: Biju Das Link: https://lore.kernel.org/r/20230412145053.114847-5-biju.das.jz@bp.renesas.com Signed-off-by: Greg Kroah-Hartman