From 854d2f241d71f6ca08ccde30e6c7c2e403363e52 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Fri, 6 Mar 2015 14:42:01 +0200 Subject: [PATCH] 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: 30c8eb52cc4a (spi: dw-mid: split rx and tx callbacks when DMA) Signed-off-by: Andy Shevchenko Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- drivers/spi/spi-dw-mid.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c index 3ce39d10fafb..4f8c798e0633 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c @@ -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); } -- 2.20.1