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authorJames Hogan <james.hogan@imgtec.com>2011-06-29 12:28:43 +0400
committerChris Ball <cjb@laptop.org>2011-07-21 01:21:05 +0400
commit03e8cb534e7cc3f71a07528a44da7ce68e5b5708 (patch)
tree989d0a96a03d8838de7617f6eb0062ed2a7065e6 /drivers/mmc
parent65d13516b2358c38ac56a5f83e989a6837dcf825 (diff)
downloadlinux-03e8cb534e7cc3f71a07528a44da7ce68e5b5708.tar.xz
mmc: dw_mmc: fix stop when fallen back to PIO
There are several situations when dw_mci_submit_data_dma() decides to fall back to PIO mode instead of using DMA, due to a short (to avoid overhead) or "complex" (e.g. with unaligned buffers) transaction, even though host->use_dma is set. However dw_mci_stop_dma() decides whether to stop DMA or set the EVENT_XFER_COMPLETE event based on host->use_dma. When falling back to PIO mode this results in data timeout errors getting missed and the driver locking up. Therefore add host->using_dma to indicate whether the current transaction is using dma or not, and adjust dw_mci_stop_dma() to use that instead. Signed-off-by: James Hogan <james.hogan@imgtec.com> Acked-by: Will Newton <will.newton@imgtec.com> Tested-by: Jaehoon Chung <jh80.chung@samsung.com> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc')
-rw-r--r--drivers/mmc/host/dw_mmc.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 10b697986283..fcff3c042f69 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -287,7 +287,7 @@ static void send_stop_cmd(struct dw_mci *host, struct mmc_data *data)
/* DMA interface functions */
static void dw_mci_stop_dma(struct dw_mci *host)
{
- if (host->use_dma) {
+ if (host->using_dma) {
host->dma_ops->stop(host);
host->dma_ops->cleanup(host);
} else {
@@ -435,6 +435,8 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
unsigned int i, direction, sg_len;
u32 temp;
+ host->using_dma = 0;
+
/* If we don't have a channel, we can't do DMA */
if (!host->use_dma)
return -ENODEV;
@@ -454,6 +456,8 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
return -EINVAL;
}
+ host->using_dma = 1;
+
if (data->flags & MMC_DATA_READ)
direction = DMA_FROM_DEVICE;
else