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Commit a0049c05 authored by Lukas Wunner's avatar Lukas Wunner Committed by Greg Kroah-Hartman
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spi: bcm2835: Fix book-keeping of DMA termination 



commit dbc944115eed48af110646992893dc43321368d8 upstream.

If submission of a DMA TX transfer succeeds but submission of the
corresponding RX transfer does not, the BCM2835 SPI driver terminates
the TX transfer but neglects to reset the dma_pending flag to false.

Thus, if the next transfer uses interrupt mode (because it is shorter
than BCM2835_SPI_DMA_MIN_LENGTH) and runs into a timeout,
dmaengine_terminate_all() will be called both for TX (once more) and
for RX (which was never started in the first place).  Fix it.

Signed-off-by: default avatarLukas Wunner <lukas@wunner.de>
Fixes: 3ecd37ed ("spi: bcm2835: enable dma modes for transfers meeting certain conditions")
Cc: stable@vger.kernel.org # v4.2+
Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Frank Pavlic <f.pavlic@kunbus.de>
Cc: Martin Sperl <kernel@martin.sperl.org>
Cc: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 708f742e

drivers/spi/spi-bcm2835.c

+1 −0
Original line number Diff line number Diff line
@@ -341,6 +341,7 @@ static int bcm2835_spi_transfer_one_dma(struct spi_master *master, 
	if (ret) {

		/* need to reset on errors */

		dmaengine_terminate_all(master->dma_tx);

		bs->dma_pending = false;

		bcm2835_spi_reset_hw(master);

		return ret;

	}