Commit 854d2f24 authored Mar 06, 2015 by Andy Shevchenko Committed by Mark Brown Mar 07, 2015

spi: dw-mid: clear BUSY flag fist and test other one



The logic of DMA completion is broken now since test_and_clear_bit() never
returns the other bit is set. It means condition are always false and we have
spi_finalize_current_transfer() called per each DMA completion which is wrong.

The patch fixes logic by clearing BUSY bit first and then check for the other
one.

Fixes: 30c8eb52 (spi: dw-mid: split rx and tx callbacks when DMA)
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

parent c9dafb27

drivers/spi/spi-dw-mid.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -108,7 +108,8 @@ static void dw_spi_dma_tx_done(void *arg)
		{
		struct dw_spi *dws = arg;

		if (test_and_clear_bit(TX_BUSY, &dws->dma_chan_busy) & BIT(RX_BUSY))
		clear_bit(TX_BUSY, &dws->dma_chan_busy);
		if (test_bit(RX_BUSY, &dws->dma_chan_busy))
		return;
		dw_spi_xfer_done(dws);
		}
		@@ -156,7 +157,8 @@ static void dw_spi_dma_rx_done(void *arg)
		{
		struct dw_spi *dws = arg;

		if (test_and_clear_bit(RX_BUSY, &dws->dma_chan_busy) & BIT(TX_BUSY))
		clear_bit(RX_BUSY, &dws->dma_chan_busy);
		if (test_bit(TX_BUSY, &dws->dma_chan_busy))
		return;
		dw_spi_xfer_done(dws);
		}

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