[PATCH] mmc: omap_hsmmc: DMA unmap only once in case of MMC error
From: S, Venkatraman <hidden>
Date: 2011-09-01 19:19:43
Also in:
linux-mmc, lkml
On Mon, Aug 29, 2011 at 3:38 AM, Per Forlin [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Reported by Russell King: ------------ mmcblk0: error -84 transferring data, sector 149201, nr 64, cmd response 0x900, card status 0xb00 mmcblk0: retrying using single block read WARNING: at /home/rmk/git/linux-2.6-rmk/lib/dma-debug.c:811 check_unmap omap_hsmmc omap_hsmmc.0: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x0000000080933000] [size=20480 bytes] ------------- In case of an error dma_unmap() is issued in omap_hsmmc_dma_cleanup() and then again in omap_hsmmc_post_req(). Resolve this by clearing the host_cookie to indicate there is no DMA mapped memory to unmap. Signed-off-by: Per Forlin <redacted> --- Bug fix on 3.1-rc3 ?drivers/mmc/host/omap_hsmmc.c | ? ?7 +++++-- ?1 files changed, 5 insertions(+), 2 deletions(-)diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 21e4a79..31d9817 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c@@ -1011,6 +1011,7 @@ static void omap_hsmmc_dma_cleanup(struct omap_hsmmc_host *host, int errno)? ? ? ? ? ? ? ? ? ? ? ?host->data->sg_len, ? ? ? ? ? ? ? ? ? ? ? ?omap_hsmmc_get_dma_dir(host, host->data)); ? ? ? ? ? ? ? ?omap_free_dma(dma_ch); + ? ? ? ? ? ? ? host->data->host_cookie = 0; ? ? ? ?} ? ? ? ?host->data = NULL; ?}@@ -1576,8 +1577,10 @@ static void omap_hsmmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,? ? ? ?struct mmc_data *data = mrq->data; ? ? ? ?if (host->use_dma) { - ? ? ? ? ? ? ? dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, - ? ? ? ? ? ? ? ? ? ? ? ? ? ?omap_hsmmc_get_dma_dir(host, data)); + ? ? ? ? ? ? ? if (data->host_cookie) + ? ? ? ? ? ? ? ? ? ? ? dma_unmap_sg(mmc_dev(host->mmc), data->sg, + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?data->sg_len, + ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?omap_hsmmc_get_dma_dir(host, data)); ? ? ? ? ? ? ? ?data->host_cookie = 0; ? ? ? ?} ?} -- 1.7.4.1
I just posted a patch [1] which just consolidates all unmapping to just post_req. This would obviously prevent double unmapping, and keeps all the related dma operations at a single place. Let me know if that works better. [1]: http://marc.info/?l=linux-mmc&m=131490406920616&w=2