Unverified Commit dc5fa590 authored by Leilk Liu's avatar Leilk Liu Committed by Mark Brown
Browse files

spi: take the SPI IO-mutex in the spi_set_cs_timing method 



this patch takes the io_mutex to prevent an unprotected HW
register modification in the set_cs_timing callback.

Fixes: 4cea6b8c ("spi: add power control when set_cs_timing")
Signed-off-by: default avatarLeilk Liu <leilk.liu@mediatek.com>
Link: https://lore.kernel.org/r/20210508060214.1485-1-leilk.liu@mediatek.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 680ec054

drivers/spi/spi.c

+7 −2
Original line number Diff line number Diff line
@@ -3457,9 +3457,12 @@ int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, 


	if (spi->controller->set_cs_timing &&

	    !(spi->cs_gpiod || gpio_is_valid(spi->cs_gpio))) {

		mutex_lock(&spi->controller->io_mutex);



		if (spi->controller->auto_runtime_pm) {

			status = pm_runtime_get_sync(parent);

			if (status < 0) {

				mutex_unlock(&spi->controller->io_mutex);

				pm_runtime_put_noidle(parent);

				dev_err(&spi->controller->dev, "Failed to power device: %d\n",

					status);
@@ -3470,11 +3473,13 @@ int spi_set_cs_timing(struct spi_device *spi, struct spi_delay *setup, 
								hold, inactive);

			pm_runtime_mark_last_busy(parent);

			pm_runtime_put_autosuspend(parent);

			return status;

		} else {

			return spi->controller->set_cs_timing(spi, setup, hold,

			status = spi->controller->set_cs_timing(spi, setup, hold,

							      inactive);

		}



		mutex_unlock(&spi->controller->io_mutex);

		return status;

	}



	if ((setup && setup->unit == SPI_DELAY_UNIT_SCK) ||