From c0da08882ef2c738edacd5e7fbca671e663f9951 Mon Sep 17 00:00:00 2001 From: Sergei Shtylyov Date: Sat, 24 Aug 2013 23:38:15 -0400 Subject: [PATCH] mmc: tmio_mmc_dma: fix PIO fallback on SDHI 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(-) diff --git a/drivers/mmc/host/tmio_mmc_dma.c b/drivers/mmc/host/tmio_mmc_dma.c index fff928604859..491e9ecc92c2 100644 --- 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 tmio_mmc_host *host) 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 tmio_mmc_host *host) 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__, -- 2.20.1