* [PATCH 1/2] mmc: core: clarify how to use post_req in case of errors
2011-08-29 13:35 [PATCH 0/2] mmc: clarifications on host.post_req() Per Forlin
@ 2011-08-29 13:35 ` Per Forlin
2011-09-12 14:05 ` Linus Walleij
2011-08-29 13:35 ` [PATCH 2/2] mmc: mmci: simplify err check in mmci_post_request Per Forlin
2011-09-21 18:30 ` [PATCH 0/2] mmc: clarifications on host.post_req() Chris Ball
2 siblings, 1 reply; 7+ messages in thread
From: Per Forlin @ 2011-08-29 13:35 UTC (permalink / raw)
To: linux-arm-kernel
The err condition in post_req() is set to undo a call made
to pre_req() that hasn't been started yet.
The err condition is not set if an MMC request returns error.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
---
drivers/mmc/core/core.c | 6 ++++++
include/linux/mmc/host.h | 3 +++
2 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 91a0a74..542aa06 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -279,8 +279,14 @@ struct mmc_async_req *mmc_start_req(struct mmc_host *host,
mmc_wait_for_req_done(host, host->areq->mrq);
err = host->areq->err_check(host->card, host->areq);
if (err) {
+ /* post process the completed failed request */
mmc_post_req(host, host->areq->mrq, 0);
if (areq)
+ /*
+ * Cancel the new prepared request, because
+ * it can't run until the failed
+ * request has been properly handled.
+ */
mmc_post_req(host, areq->mrq, -EINVAL);
host->areq = NULL;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 1d09562..7896fb4 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -108,6 +108,9 @@ struct mmc_host_ops {
* It is optional for the host to implement pre_req and post_req in
* order to support double buffering of requests (prepare one
* request while another request is active).
+ * pre_req() must always be followed by a post_req().
+ * To undo a call made to pre_req(), call post_req() with
+ * a nonzero err condition.
*/
void (*post_req)(struct mmc_host *host, struct mmc_request *req,
int err);
--
1.7.4.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/2] mmc: mmci: simplify err check in mmci_post_request
2011-08-29 13:35 [PATCH 0/2] mmc: clarifications on host.post_req() Per Forlin
2011-08-29 13:35 ` [PATCH 1/2] mmc: core: clarify how to use post_req in case of errors Per Forlin
@ 2011-08-29 13:35 ` Per Forlin
2011-09-12 14:06 ` Linus Walleij
2011-09-21 18:30 ` [PATCH 0/2] mmc: clarifications on host.post_req() Chris Ball
2 siblings, 1 reply; 7+ messages in thread
From: Per Forlin @ 2011-08-29 13:35 UTC (permalink / raw)
To: linux-arm-kernel
The error condition indicates that mmci_post_request() should cleanup
after the mmci_pre_request(). In this case the resources allocated by
device_prep_slave_sg() are freed by calling dmaengine_terminate_all().
dma_unmap_sg() should always be performed if the host_cookie is set.
Signed-off-by: Per Forlin <per.forlin@linaro.org>
---
drivers/mmc/host/mmci.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 56e9a41..40e4c05 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -529,7 +529,7 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
if (chan) {
if (err)
dmaengine_terminate_all(chan);
- if (err || data->host_cookie)
+ if (data->host_cookie)
dma_unmap_sg(mmc_dev(host->mmc), data->sg,
data->sg_len, dir);
mrq->data->host_cookie = 0;
--
1.7.4.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 0/2] mmc: clarifications on host.post_req()
2011-08-29 13:35 [PATCH 0/2] mmc: clarifications on host.post_req() Per Forlin
2011-08-29 13:35 ` [PATCH 1/2] mmc: core: clarify how to use post_req in case of errors Per Forlin
2011-08-29 13:35 ` [PATCH 2/2] mmc: mmci: simplify err check in mmci_post_request Per Forlin
@ 2011-09-21 18:30 ` Chris Ball
2011-09-21 18:43 ` Per Fridén Förlin
2 siblings, 1 reply; 7+ messages in thread
From: Chris Ball @ 2011-09-21 18:30 UTC (permalink / raw)
To: linux-arm-kernel
Hi Per,
On Mon, Aug 29 2011, Per Forlin wrote:
> Fixes for 3.1.
> This patchset doesn't fix any bugs in 3.1 but it improves the documentation
> in order to prevent new bugs.
I've merged this into mmc-next now, but I'm planning on sending it for
3.2 instead of 3.1 at this point; hope that's okay.
Thanks,
- Chris.
--
Chris Ball <cjb@laptop.org> <http://printf.net/>
One Laptop Per Child
^ permalink raw reply [flat|nested] 7+ messages in thread