| From | Ben Hutchings <> | Date | Mon, 21 Oct 2013 09:46:28 +0100 | Subject | [PATCH 3.2 034/149] mmc: tmio_mmc_dma: fix PIO fallback on SDHI |
| |
3.2.52-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
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 <sergei.shtylyov@cogentembedded.com> Acked-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- 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__,
|