On Wednesday, January 22, 2014 06:11 PM, Russell King - ARM Linux wrote:
On Wed, Jan 22, 2014 at 12:32:39PM +0800, Chris Ruehl wrote:
diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index f7199c8..8645d6a 100644
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -347,7 +347,7 @@ static int mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
return 0;
for_each_sg(data->sg, sg, data->sg_len, i) {
- if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
+ if (sg && (sg->offset & 3 || sg->length & 3 || sg->length < 512)) {
sg should never be NULL here - so this is probably papering over a bug.
I'd had some time and look into the meaning of the sg->xx & 0x3 and
understand this
check validate the alignment of the data. If failed the dma handling is
canceled and a fall-back to pio is done.
In a earlier patch for the unexpected dma & interrupts are synchronized
using the spinlock. I pickup this
idea and protect the setup-data using a look. Until now the oops are gone.
PLEASE comment!
diff --git a/drivers/mmc/host/mxcmmc.c b/drivers/mmc/host/mxcmmc.c
index 8645d6a..b11d3c4 100644
--- a/drivers/mmc/host/mxcmmc.c
+++ b/drivers/mmc/host/mxcmmc.c
@@ -347,7 +347,7 @@ static int mxcmci_setup_data(struct mxcmci_host
*host, struct mmc_data *data)
return 0;
for_each_sg(data->sg, sg, data->sg_len, i) {
- if (sg && (sg->offset & 3 || sg->length & 3 ||
sg->length < 512)) {
+ if (sg->offset & 3 || sg->length & 3 || sg->length < 512) {
host->do_dma = 0;
return 0;
}
@@ -800,9 +800,12 @@ static void mxcmci_request(struct mmc_host *mmc,
struct mmc_request *req)
struct mxcmci_host *host = mmc_priv(mmc);
unsigned int cmdat = host->cmdat;
int error;
+ unsigned long flags;
WARN_ON(host->req != NULL);
+ spin_lock_irqsave(&host->lock, flags);
+
host->req = req;
host->cmdat &= ~CMD_DAT_CONT_INIT;
@@ -813,6 +816,7 @@ static void mxcmci_request(struct mmc_host *mmc,
struct mmc_request *req)
error = mxcmci_setup_data(host, req->data);
if (error) {
req->cmd->error = error;
+ spin_unlock_irqrestore(&host->lock, flags);
goto out;
}
@@ -823,6 +827,8 @@ static void mxcmci_request(struct mmc_host *mmc,
struct mmc_request *req)
cmdat |= CMD_DAT_CONT_WRITE;
}
+ spin_unlock_irqrestore(&host->lock, flags);
With kind regards
Chris
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