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| author |   Russell King <rmk+kernel@arm.linux.org.uk> | 2016-01-26 13:40:37 +0000 |
|---|---|---|
| committer |   Ulf Hansson <ulf.hansson@linaro.org> | 2016-02-29 11:03:22 +0100 |
| commit | 94538e51d67da97e798d379d6bcf3d386d609bfb (patch) | |
| tree | 5c78bf6836b36b206a89a23171566f92ea988dac /drivers/mmc/host/sdhci.h | |
| parent | mmc: sdhci: always unmap a mapped data transfer in sdhci_post_req() (diff) | |
| download | linux-dev-94538e51d67da97e798d379d6bcf3d386d609bfb.tar.xz linux-dev-94538e51d67da97e798d379d6bcf3d386d609bfb.zip | |
mmc: sdhci: clean up host cookie handling
Commit d31911b9374a ("mmc: sdhci: fix dma memory leak in sdhci_pre_req()")
added a complicated method to manage the DMA map state for the data
transfer, but this complexity is not required.
There are three states:
* Unmapped
* Mapped by sdhci_pre_req()
* Mapped by sdhci_prepare_data()
sdhci_prepare_data() needs to know when the data buffers have been
successfully mapped by sdhci_pre_req(), and if so, there is no need to
map them a second time.
When we come to tear down the mapping, we want to know whether
sdhci_post_req() will be called (which is determined by sdhci_pre_req()
having been previously called) so that we can postpone the unmap
operation.
Hence, it makes sense to simply record when the successful DMA map
happened (via COOKIE_PRE_MAPPED vs COOKIE_MAPPED) rather than having
the complex mechanics involving COOKIE_MAPPED vs COOKIE_GIVEN.
If a mapping is created by sdhci_prepare_data(), we must tear it down
ourselves, without waiting for sdhci_post_req() (hence, the new
COOKIE_MAPPED case). If the mapping is created by sdhci_pre_req()
then sdhci_post_req() is responsible for tearing the mapping down.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
Diffstat (limited to 'drivers/mmc/host/sdhci.h')
| -rw-r--r-- | drivers/mmc/host/sdhci.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 0115e9907bf8..3bd28033dbd9 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -316,8 +316,8 @@ struct sdhci_adma2_64_desc { enum sdhci_cookie { COOKIE_UNMAPPED, - COOKIE_MAPPED, - COOKIE_GIVEN, + COOKIE_PRE_MAPPED, /* mapped by sdhci_pre_req() */ + COOKIE_MAPPED, /* mapped by sdhci_prepare_data() */ }; struct sdhci_host { |