| From f936f9b67b7f8c2eae01dd303a0e90bd777c4679 Mon Sep 17 00:00:00 2001 |
| From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> |
| Date: Sat, 24 Aug 2013 23:38:15 -0400 |
| Subject: mmc: tmio_mmc_dma: fix PIO fallback on SDHI |
| |
| 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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| 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__, |
