spi: atmel: fixed spin_lock usage inside atmel_spi_remove

BugLink: http://bugs.launchpad.net/bugs/1764316

[ Upstream commit 66e900a3 ]

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>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

drivers/spi/spi-atmel.c

@@ -1669,12 +1669,12 @@ static int atmel_spi_remove(struct platform_device *pdev)
 	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);