3.2.52-rc1 review patch. If anyone has any objections, please let me know.
------------------ From: Sergei Shtylyov <[email protected]> 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 <[email protected]> Acked-by: Guennadi Liakhovetski <[email protected]> Signed-off-by: Chris Ball <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- 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 @@ -92,6 +92,7 @@ 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; @@ -104,7 +105,6 @@ 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__, @@ -173,6 +173,7 @@ 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; @@ -185,7 +186,6 @@ 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__, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
