@@ -431,12 +431,12 @@ static int sdhci_pre_dma_transfer(struct sdhci_host *host,
{
int sg_count;
- if (data->host_cookie == COOKIE_MAPPED) {
- data->host_cookie = COOKIE_GIVEN;
+ /*
+ * If the data buffers are already mapped, return the previous
+ * dma_map_sg() result.
+ */
+ if (data->host_cookie == COOKIE_PRE_MAPPED)
return data->sg_count;
- }
-
- WARN_ON(data->host_cookie == COOKIE_GIVEN);
sg_count = dma_map_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
data->flags & MMC_DATA_WRITE ?
@@ -2093,7 +2093,7 @@ static void sdhci_pre_req(struct mmc_host *mmc, struct mmc_request *mrq,
mrq->data->host_cookie = COOKIE_UNMAPPED;
if (host->flags & SDHCI_REQ_USE_DMA)
- sdhci_pre_dma_transfer(host, mrq->data, COOKIE_MAPPED);
+ sdhci_pre_dma_transfer(host, mrq->data, COOKIE_PRE_MAPPED);
}
static void sdhci_card_event(struct mmc_host *mmc)
@@ -311,8 +311,8 @@ 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 {
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> --- drivers/mmc/host/sdhci.c | 12 ++++++------ drivers/mmc/host/sdhci.h | 4 ++-- 2 files changed, 8 insertions(+), 8 deletions(-)