[PATCH 5.4 122/214] spi: stm32h7: fix race condition at end of transfer

From: Greg Kroah-Hartman
Date: Tue Sep 01 2020 - 11:32:38 EST


From: Antonio Borneo <antonio.borneo@xxxxxx>

[ Upstream commit 135dd873d3c76d812ae64c668adef3f2c59ed27f ]

The caller of stm32_spi_transfer_one(), spi_transfer_one_message(),
is waiting for us to call spi_finalize_current_transfer() and will
eventually schedule a new transfer, if available.
We should guarantee that the spi controller is really available
before calling spi_finalize_current_transfer().

Move the call to spi_finalize_current_transfer() _after_ the call
to stm32_spi_disable().

Signed-off-by: Antonio Borneo <antonio.borneo@xxxxxx>
Signed-off-by: Alain Volmat <alain.volmat@xxxxxx>
Link: https://lore.kernel.org/r/1597043558-29668-2-git-send-email-alain.volmat@xxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/spi/spi-stm32.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
index dc6334f67e6ae..25b1348aaa549 100644
--- a/drivers/spi/spi-stm32.c
+++ b/drivers/spi/spi-stm32.c
@@ -967,8 +967,8 @@ static irqreturn_t stm32h7_spi_irq_thread(int irq, void *dev_id)
spin_unlock_irqrestore(&spi->lock, flags);

if (end) {
- spi_finalize_current_transfer(master);
stm32h7_spi_disable(spi);
+ spi_finalize_current_transfer(master);
}

return IRQ_HANDLED;
--
2.25.1