[PATCH AUTOSEL for 3.18 05/24] spi: atmel: fixed spin_lock usage inside atmel_spi_remove

From: Sasha Levin
Date: Sat Feb 03 2018 - 13:21:44 EST


From: Radu Pirea <radu.pirea@xxxxxxxxxxxxx>

[ Upstream commit 66e900a3d225575c8b48b59ae1fe74bb6e5a65cc ]

The only part of atmel_spi_remove which needs to be atomic is hardware
reset.

atmel_spi_stop_dma calls dma_terminate_all and this needs interrupts
enabled.
atmel_spi_release_dma calls dma_release_channel and dma_release_channel
locks a mutex inside of spin_lock.

So the call of these functions can't be inside a spin_lock.

Reported-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Signed-off-by: Radu Pirea <radu.pirea@xxxxxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
drivers/spi/spi-atmel.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 4bf337aa4fd5..fab124d3b8a6 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -1416,12 +1416,12 @@ static int atmel_spi_remove(struct platform_device *pdev)
struct atmel_spi *as = spi_master_get_devdata(master);

/* reset the hardware and block queue progress */
- spin_lock_irq(&as->lock);
if (as->use_dma) {
atmel_spi_stop_dma(as);
atmel_spi_release_dma(as);
}

+ spin_lock_irq(&as->lock);
spi_writel(as, CR, SPI_BIT(SWRST));
spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */
spi_readl(as, SR);
--
2.11.0