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    Subject[PATCH 3.18 06/24] spi: atmel: fixed spin_lock usage inside atmel_spi_remove
    Date
    3.18-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    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
    @@ -1416,12 +1416,12 @@ static int atmel_spi_remove(struct platf
    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);

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