Before switching back to the right partition in mmc_blk_reset
there used to be a check if hw_reset was even supported.
This return value was removed, so there is no reason to check.
Furthermore ensure part_curr is not falsely set to a valid value
on reset or partition switch error.
Fixes: fefdd3c91e0a ("mmc: core: Drop superfluous validations in mmc_hw|sw_reset()")
Cc: [email protected]
Signed-off-by: Christian Loehle <[email protected]>
---
-v3: Ensure invalid part_curr on error
-v2: Do not attempt to switch partitions if reset failed
drivers/mmc/core/block.c | 29 ++++++++++++++---------------
1 file changed, 14 insertions(+), 15 deletions(-)
diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index ce89611a136e..45a44edcc31a 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -134,6 +134,7 @@ struct mmc_blk_data {
* track of the current selected device partition.
*/
unsigned int part_curr;
+#define MMC_BLK_PART_INVALID UINT_MAX /* Unknown partition active */
int area_type;
/* debugfs files (only in main mmc_blk_data) */
@@ -991,29 +992,27 @@ static int mmc_blk_reset(struct mmc_blk_data *md, struct mmc_host *host,
int type)
{
int err;
+ struct mmc_blk_data *main_md = dev_get_drvdata(&host->card->dev);
+ int part_err;
if (md->reset_done & type)
return -EEXIST;
md->reset_done |= type;
+ main_md->part_curr = MMC_BLK_PART_INVALID;
err = mmc_hw_reset(host->card);
+ if (err)
+ return err;
/* Ensure we switch back to the correct partition */
- if (err) {
- struct mmc_blk_data *main_md =
- dev_get_drvdata(&host->card->dev);
- int part_err;
-
- main_md->part_curr = main_md->part_type;
- part_err = mmc_blk_part_switch(host->card, md->part_type);
- if (part_err) {
- /*
- * We have failed to get back into the correct
- * partition, so we need to abort the whole request.
- */
- return -ENODEV;
- }
+ part_err = mmc_blk_part_switch(host->card, md->part_type);
+ if (part_err) {
+ /*
+ * We have failed to get back into the correct
+ * partition, so we need to abort the whole request.
+ */
+ return -ENODEV;
}
- return err;
+ return 0;
}
static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int type)
--
2.37.3
Hyperstone GmbH | Reichenaustr. 39a | 78467 Konstanz
Managing Director: Dr. Jan Peter Berns.
Commercial register of local courts: Freiburg HRB381782
On Mon, 10 Oct 2022 at 16:03, Christian Löhle <[email protected]> wrote:
>
> Before switching back to the right partition in mmc_blk_reset
> there used to be a check if hw_reset was even supported.
> This return value was removed, so there is no reason to check.
> Furthermore ensure part_curr is not falsely set to a valid value
> on reset or partition switch error.
>
> Fixes: fefdd3c91e0a ("mmc: core: Drop superfluous validations in mmc_hw|sw_reset()")
> Cc: [email protected]
>
> Signed-off-by: Christian Loehle <[email protected]>
This looks good to me, however I am awaiting and ack from Adrian
before applying, to make sure we are all aligned with the approach.
Kind regards
Uffe
> ---
> -v3: Ensure invalid part_curr on error
> -v2: Do not attempt to switch partitions if reset failed
>
> drivers/mmc/core/block.c | 29 ++++++++++++++---------------
> 1 file changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index ce89611a136e..45a44edcc31a 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -134,6 +134,7 @@ struct mmc_blk_data {
> * track of the current selected device partition.
> */
> unsigned int part_curr;
> +#define MMC_BLK_PART_INVALID UINT_MAX /* Unknown partition active */
> int area_type;
>
> /* debugfs files (only in main mmc_blk_data) */
> @@ -991,29 +992,27 @@ static int mmc_blk_reset(struct mmc_blk_data *md, struct mmc_host *host,
> int type)
> {
> int err;
> + struct mmc_blk_data *main_md = dev_get_drvdata(&host->card->dev);
> + int part_err;
>
> if (md->reset_done & type)
> return -EEXIST;
>
> md->reset_done |= type;
> + main_md->part_curr = MMC_BLK_PART_INVALID;
> err = mmc_hw_reset(host->card);
> + if (err)
> + return err;
> /* Ensure we switch back to the correct partition */
> - if (err) {
> - struct mmc_blk_data *main_md =
> - dev_get_drvdata(&host->card->dev);
> - int part_err;
> -
> - main_md->part_curr = main_md->part_type;
> - part_err = mmc_blk_part_switch(host->card, md->part_type);
> - if (part_err) {
> - /*
> - * We have failed to get back into the correct
> - * partition, so we need to abort the whole request.
> - */
> - return -ENODEV;
> - }
> + part_err = mmc_blk_part_switch(host->card, md->part_type);
> + if (part_err) {
> + /*
> + * We have failed to get back into the correct
> + * partition, so we need to abort the whole request.
> + */
> + return -ENODEV;
> }
> - return err;
> + return 0;
> }
>
> static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int type)
> --
> 2.37.3
> Hyperstone GmbH | Reichenaustr. 39a | 78467 Konstanz
> Managing Director: Dr. Jan Peter Berns.
> Commercial register of local courts: Freiburg HRB381782
>
On Tue, 11 Oct 2022 at 12:15, Adrian Hunter <[email protected]> wrote:
>
> On 10/10/22 17:03, Christian Löhle wrote:
> > Before switching back to the right partition in mmc_blk_reset
> > there used to be a check if hw_reset was even supported.
> > This return value was removed, so there is no reason to check.
> > Furthermore ensure part_curr is not falsely set to a valid value
> > on reset or partition switch error.
> >
> > Fixes: fefdd3c91e0a ("mmc: core: Drop superfluous validations in mmc_hw|sw_reset()")
> > Cc: [email protected]
> >
> > Signed-off-by: Christian Loehle <[email protected]>
> > ---
> > -v3: Ensure invalid part_curr on error
> > -v2: Do not attempt to switch partitions if reset failed
> >
> > drivers/mmc/core/block.c | 29 ++++++++++++++---------------
> > 1 file changed, 14 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> > index ce89611a136e..45a44edcc31a 100644
> > --- a/drivers/mmc/core/block.c
> > +++ b/drivers/mmc/core/block.c
> > @@ -134,6 +134,7 @@ struct mmc_blk_data {
> > * track of the current selected device partition.
> > */
> > unsigned int part_curr;
> > +#define MMC_BLK_PART_INVALID UINT_MAX /* Unknown partition active */
> > int area_type;
> >
> > /* debugfs files (only in main mmc_blk_data) */
> > @@ -991,29 +992,27 @@ static int mmc_blk_reset(struct mmc_blk_data *md, struct mmc_host *host,
> > int type)
> > {
> > int err;
> > + struct mmc_blk_data *main_md = dev_get_drvdata(&host->card->dev);
> > + int part_err;
> >
> > if (md->reset_done & type)
> > return -EEXIST;
> >
> > md->reset_done |= type;
> > + main_md->part_curr = MMC_BLK_PART_INVALID;
>
> This forces a partition switch even if it is not necessary.
Right, very good point!
>
> > err = mmc_hw_reset(host->card);
>
> This would be better:
>
> /*
> * A successful reset will leave the card in the main partition, but
> * upon failure it might not be, so set it to MMC_BLK_PART_INVALID
> * in that case.
> */
> main_md->part_curr = err ? MMC_BLK_PART_INVALID : main_md->part_type;
>
Yes! And the comment is valuable too!
[...]
Kind regards
Uffe
On 10/10/22 17:03, Christian Löhle wrote:
> Before switching back to the right partition in mmc_blk_reset
> there used to be a check if hw_reset was even supported.
> This return value was removed, so there is no reason to check.
> Furthermore ensure part_curr is not falsely set to a valid value
> on reset or partition switch error.
>
> Fixes: fefdd3c91e0a ("mmc: core: Drop superfluous validations in mmc_hw|sw_reset()")
> Cc: [email protected]
>
> Signed-off-by: Christian Loehle <[email protected]>
> ---
> -v3: Ensure invalid part_curr on error
> -v2: Do not attempt to switch partitions if reset failed
>
> drivers/mmc/core/block.c | 29 ++++++++++++++---------------
> 1 file changed, 14 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
> index ce89611a136e..45a44edcc31a 100644
> --- a/drivers/mmc/core/block.c
> +++ b/drivers/mmc/core/block.c
> @@ -134,6 +134,7 @@ struct mmc_blk_data {
> * track of the current selected device partition.
> */
> unsigned int part_curr;
> +#define MMC_BLK_PART_INVALID UINT_MAX /* Unknown partition active */
> int area_type;
>
> /* debugfs files (only in main mmc_blk_data) */
> @@ -991,29 +992,27 @@ static int mmc_blk_reset(struct mmc_blk_data *md, struct mmc_host *host,
> int type)
> {
> int err;
> + struct mmc_blk_data *main_md = dev_get_drvdata(&host->card->dev);
> + int part_err;
>
> if (md->reset_done & type)
> return -EEXIST;
>
> md->reset_done |= type;
> + main_md->part_curr = MMC_BLK_PART_INVALID;
This forces a partition switch even if it is not necessary.
> err = mmc_hw_reset(host->card);
This would be better:
/*
* A successful reset will leave the card in the main partition, but
* upon failure it might not be, so set it to MMC_BLK_PART_INVALID
* in that case.
*/
main_md->part_curr = err ? MMC_BLK_PART_INVALID : main_md->part_type;
> + if (err)
> + return err;
There was a time when mmc requests would be retried directly without
going back through the block layer. I don't think that can happen
anymore after a failed reset. However, if you are going to skip the
partition switch, the commit message needs to explain that you have
checked the code paths and we never retry a request directly after a
failed reset. Also a comment is needed to say the same.
> /* Ensure we switch back to the correct partition */
> - if (err) {
> - struct mmc_blk_data *main_md =
> - dev_get_drvdata(&host->card->dev);
> - int part_err;
> -
> - main_md->part_curr = main_md->part_type;
> - part_err = mmc_blk_part_switch(host->card, md->part_type);
> - if (part_err) {
> - /*
> - * We have failed to get back into the correct
> - * partition, so we need to abort the whole request.
> - */
> - return -ENODEV;
> - }
> + part_err = mmc_blk_part_switch(host->card, md->part_type);
> + if (part_err) {
Don't really need part_err. i.e. could be
if (mmc_blk_part_switch(host->card, md->part_type) {
> + /*
> + * We have failed to get back into the correct
> + * partition, so we need to abort the whole request.
> + */
> + return -ENODEV;
> }
> - return err;
> + return 0;
> }
>
> static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int type)