Searched hist:"94538 e51" (Results 1 – 2 of 2) sorted by relevance
/openbmc/linux/drivers/mmc/host/ |
H A D | sdhci.h | 94538e51 Tue Jan 26 07:40:37 CST 2016 Russell King <rmk+kernel@arm.linux.org.uk> 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> 94538e51 Tue Jan 26 07:40:37 CST 2016 Russell King <rmk+kernel@arm.linux.org.uk> 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>
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H A D | sdhci.c | 94538e51 Tue Jan 26 07:40:37 CST 2016 Russell King <rmk+kernel@arm.linux.org.uk> 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>
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