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, Sergei Shtylyov , Guennadi Liakhovetski , Chris Ball Subject: [ 110/117] mmc: tmio_mmc_dma: fix PIO fallback on SDHI Date: Tue, 24 Sep 2013 17:19:36 -0700 Message-Id: <20130925001752.953317344@linuxfoundation.org> In-Reply-To: <20130925001740.833541979@linuxfoundation.org> References: <20130925001740.833541979@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sergei Shtylyov commit f936f9b67b7f8c2eae01dd303a0e90bd777c4679 upstream. I'm testing SH-Mobile SDHI driver in DMA mode with a new DMA controller using 'bonnie++' and getting DMA error after which the tmio_mmc_dma.c code falls back to PIO but all commands time out after that. It turned out that the fallback code calls tmio_mmc_enable_dma() with RX/TX channels already freed and pointers to them cleared, so that the function bails out early instead of clearing the DMA bit in the CTL_DMA_ENABLE register. The regression was introduced by commit 162f43e31c5a376ec16336e5d0ac973373d54c89 (mmc: tmio: fix a deadlock). Moving tmio_mmc_enable_dma() calls to the top of the PIO fallback code in tmio_mmc_start_dma_{rx|tx}() helps. Signed-off-by: Sergei Shtylyov Acked-by: Guennadi Liakhovetski Signed-off-by: Chris Ball Signed-off-by: Greg Kroah-Hartman --- drivers/mmc/host/tmio_mmc_dma.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/mmc/host/tmio_mmc_dma.c +++ b/drivers/mmc/host/tmio_mmc_dma.c @@ -104,6 +104,7 @@ static void tmio_mmc_start_dma_rx(struct pio: if (!desc) { /* DMA failed, fall back to PIO */ + tmio_mmc_enable_dma(host, false); if (ret >= 0) ret = -EIO; host->chan_rx = NULL; @@ -116,7 +117,6 @@ pio: } dev_warn(&host->pdev->dev, "DMA failed: %d, falling back to PIO\n", ret); - tmio_mmc_enable_dma(host, false); } dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d, sg[%d]\n", __func__, @@ -185,6 +185,7 @@ static void tmio_mmc_start_dma_tx(struct pio: if (!desc) { /* DMA failed, fall back to PIO */ + tmio_mmc_enable_dma(host, false); if (ret >= 0) ret = -EIO; host->chan_tx = NULL; @@ -197,7 +198,6 @@ pio: } dev_warn(&host->pdev->dev, "DMA failed: %d, falling back to PIO\n", ret); - tmio_mmc_enable_dma(host, false); } dev_dbg(&host->pdev->dev, "%s(): desc %p, cookie %d\n", __func__,