From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Shevchenko , Mark Brown Subject: [PATCH 3.19 65/75] spi: dw-mid: clear BUSY flag fist and test other one Date: Fri, 10 Apr 2015 15:19:31 +0200 Message-Id: <20150410131710.887826564@linuxfoundation.org> In-Reply-To: <20150410131707.794709951@linuxfoundation.org> References: <20150410131707.794709951@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andy Shevchenko commit 854d2f241d71f6ca08ccde30e6c7c2e403363e52 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- drivers/spi/spi-dw-mid.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- 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); }