spi: dw-mid: clear BUSY flag fist and test other one
authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Fri, 6 Mar 2015 12:42:01 +0000 (14:42 +0200)
committerMark Brown <broonie@kernel.org>
Sat, 7 Mar 2015 11:22:02 +0000 (11:22 +0000)
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: 30c8eb52cc4a (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
drivers/spi/spi-dw-mid.c

index 3ce39d10fafbc270d47a17107b7cc5ce257dca94..4f8c798e0633a81483c3b05af46805b1848ba386 100644 (file)
@@ -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);
 }