[PATCH 4/7] mmc: bcm2835: Avoid possible races on data requests
From: Stefan Wahren <hidden>
Date: 2018-11-11 13:45:27
Also in:
linux-mmc
Subsystem:
multimedia card (mmc), secure digital (sd) and sdio subsystem, the rest · Maintainers:
Ulf Hansson, Linus Torvalds
There are two accesses on the data requests which are not protected by the mutex. So fix this accordingly. Signed-off-by: Stefan Wahren <redacted> --- drivers/mmc/host/bcm2835.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/bcm2835.c b/drivers/mmc/host/bcm2835.c
index 45724ef..1c60798 100644
--- a/drivers/mmc/host/bcm2835.c
+++ b/drivers/mmc/host/bcm2835.c@@ -1064,10 +1064,12 @@ static void bcm2835_dma_complete_work(struct work_struct *work) { struct bcm2835_host *host = container_of(work, struct bcm2835_host, dma_work); - struct mmc_data *data = host->data; + struct mmc_data *data; mutex_lock(&host->mutex); + data = host->data; + if (host->dma_chan) { dma_unmap_sg(host->dma_chan->device->dev, data->sg, data->sg_len,
@@ -1192,9 +1194,6 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) return; } - if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD)) - bcm2835_prepare_dma(host, mrq->data); - mutex_lock(&host->mutex); WARN_ON(host->mrq);
@@ -1218,6 +1217,9 @@ static void bcm2835_request(struct mmc_host *mmc, struct mmc_request *mrq) return; } + if (host->use_dma && mrq->data && (mrq->data->blocks > PIO_THRESHOLD)) + bcm2835_prepare_dma(host, mrq->data); + host->use_sbc = !!mrq->sbc && host->mrq->data && (host->mrq->data->flags & MMC_DATA_READ); if (host->use_sbc) {
--
2.7.4