This is a note to let you know that I've just added the patch titled

spi: atmel: fixed spin_lock usage inside atmel_spi_remove

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: spi-atmel-fixed-spin_lock-usage-inside-atmel_spi_remove.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Wed Feb 28 16:19:30 CET 2018

From: Radu Pirea radu.pirea@microchip.com Date: Fri, 15 Dec 2017 17:40:17 +0200 Subject: spi: atmel: fixed spin_lock usage inside atmel_spi_remove

From: Radu Pirea radu.pirea@microchip.com

[ 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@gmail.com Signed-off-by: Radu Pirea radu.pirea@microchip.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/spi/spi-atmel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -1669,12 +1669,12 @@ static int atmel_spi_remove(struct platf pm_runtime_get_sync(&pdev->dev);

/* 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);

Patches currently in stable-queue which might be from radu.pirea@microchip.com are

queue-4.4/spi-atmel-fixed-spin_lock-usage-inside-atmel_spi_remove.patch