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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2016-01-26 13:40:53 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-12 07:33:44 -0700 |
| commit | ef9ddac5e4640ce6ae78cc70f2b2b1cb80b1e8ac (patch) | |
| tree | 6db7f7afc82b3353eb83a2ea598541f72f6efcb3 /drivers | |
| parent | ef78a0cea7c57d9326fefc525b57bd365c563fd0 (diff) | |
| download | lwn-ef9ddac5e4640ce6ae78cc70f2b2b1cb80b1e8ac.tar.gz lwn-ef9ddac5e4640ce6ae78cc70f2b2b1cb80b1e8ac.zip | |
mmc: sdhci: further fix for DMA unmapping in sdhci_post_req()
commit 771a3dc225815b7cc691c1ce703a3af8488e48df upstream.
sdhci_post_req() exists to unmap a previously mapped but already
finished request, while the next request is in progress. However, the
state of the SDHCI_REQ_USE_DMA flag depends on the last submitted
request.
This means we can end up clearing the flag due to a quirk, which then
means that sdhci_post_req() fails to unmap the DMA buffer, potentially
leading to data corruption.
We can safely ignore the SDHCI_REQ_USE_DMA here, as testing
data->host_cookie is entirely sufficient.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
[ Re-based to apply as a separate fix ]
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/mmc/host/sdhci.c | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 8ca39085803b..2d0172bc821f 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2115,14 +2115,13 @@ static void sdhci_post_req(struct mmc_host *mmc, struct mmc_request *mrq, struct sdhci_host *host = mmc_priv(mmc); struct mmc_data *data = mrq->data; - if (host->flags & SDHCI_REQ_USE_DMA) { - if (data->host_cookie == COOKIE_GIVEN || - data->host_cookie == COOKIE_MAPPED) - dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, - data->flags & MMC_DATA_WRITE ? - DMA_TO_DEVICE : DMA_FROM_DEVICE); - data->host_cookie = COOKIE_UNMAPPED; - } + if (data->host_cookie == COOKIE_GIVEN || + data->host_cookie == COOKIE_MAPPED) + dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len, + data->flags & MMC_DATA_WRITE ? + DMA_TO_DEVICE : DMA_FROM_DEVICE); + + data->host_cookie = COOKIE_UNMAPPED; } static int sdhci_pre_dma_transfer(struct sdhci_host *host, |