[U-Boot] [PATCH v2] mmc: Update "mmc->part_num" when performing a partition switch
When running the "save" command several times on a mx6qsabresd we see:
U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed
Fix this by updating mmc->part_num inside mmc_switch_part() after a succesful mmc partition switch.
After this fix, we no longer see the error after the "save" command on a mx6qsabresd. Also tested on a mx53loco.
Reported-by: Jason Liu r64343@freescale.com
Signed-off-by: Fabio Estevam fabio.estevam@freescale.com --- Changes since v1: - Do the change inside the mmc core
drivers/mmc/mmc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 2590f1b..7f568ed 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -680,14 +680,20 @@ static int mmc_change_freq(struct mmc *mmc)
int mmc_switch_part(int dev_num, unsigned int part_num) { + int ret; struct mmc *mmc = find_mmc_device(dev_num);
if (!mmc) return -1;
- return mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONF, + ret = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONF, (mmc->part_config & ~PART_ACCESS_MASK) | (part_num & PART_ACCESS_MASK)); + + if (!ret) + mmc->part_num = part_num; + + return ret; }
int mmc_getcd(struct mmc *mmc)
On 06/04/2013 01:17 PM, Fabio Estevam wrote:
When running the "save" command several times on a mx6qsabresd we see:
U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed
Fix this by updating mmc->part_num inside mmc_switch_part() after a succesful mmc partition switch.
This surely has exactly the same issue as the previous version, where the update of part_num was done inside common/env_mmc.c?
On Tue, Jun 4, 2013 at 4:21 PM, Stephen Warren swarren@wwwdotorg.org wrote:
This surely has exactly the same issue as the previous version, where the update of part_num was done inside common/env_mmc.c?
My understading is that the mmc core should update mmc->part_num and I don't see such update, or am I missing something?
Thanks,
Fabio Estevam
On 06/04/2013 01:30 PM, Fabio Estevam wrote:
On Tue, Jun 4, 2013 at 4:21 PM, Stephen Warren swarren@wwwdotorg.org wrote:
This surely has exactly the same issue as the previous version, where the update of part_num was done inside common/env_mmc.c?
My understading is that the mmc core should update mmc->part_num and I don't see such update, or am I missing something?
That seems like a reasonable way for the code to work. However, you'd need to modify common/env_mmc.c:init_mmc_for_env() so that it saves off mmc->part_num before switching MMC partitions, so that fini_mmc_for_env() knows which partition to switch back to. Right now, it relies on the fact that mmc_switch_part() does not update mmc->part_num, and hence uses that value to save the previously selected partition ID.
Also, if you make this change, I think you can update common/cmd_mmc.c:do_mmcops(), since it will no longer need to update mmc->part_num after a successful switch.
Hi Stephen,
On Tue, Jun 4, 2013 at 4:36 PM, Stephen Warren swarren@wwwdotorg.org wrote:
That seems like a reasonable way for the code to work. However, you'd need to modify common/env_mmc.c:init_mmc_for_env() so that it saves off mmc->part_num before switching MMC partitions, so that fini_mmc_for_env() knows which partition to switch back to. Right now, it relies on the fact that mmc_switch_part() does not update mmc->part_num, and hence uses that value to save the previously selected partition ID.
Also, if you make this change, I think you can update common/cmd_mmc.c:do_mmcops(), since it will no longer need to update mmc->part_num after a successful switch.
I understood your second suggestion and did the changes below, but I am not sure on the first one regarding the change you proposed inside init_mmc_for_env().
Here is what I did so far:
diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c index 7d82469..20a2792 100644 --- a/common/cmd_mmc.c +++ b/common/cmd_mmc.c @@ -243,8 +243,6 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
if (part != mmc->part_num) { ret = mmc_switch_part(dev, part); - if (!ret) - mmc->part_num = part;
printf("switch to partions #%d, %s\n", part, (!ret) ? "OK" : "ERROR"); diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 0a2f535..e8d2ea6 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -702,14 +702,20 @@ static int mmc_change_freq(struct mmc *mmc)
int mmc_switch_part(int dev_num, unsigned int part_num) { + int ret; struct mmc *mmc = find_mmc_device(dev_num);
if (!mmc) return -1;
- return mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONF, + ret = mmc_switch(mmc, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONF, (mmc->part_config & ~PART_ACCESS_MASK) | (part_num & PART_ACCESS_MASK)); + + if (!ret) + mmc->part_num = part_num; + + return ret; }
int mmc_getcd(struct mmc *mmc)
On 06/04/2013 02:45 PM, Fabio Estevam wrote:
Hi Stephen,
On Tue, Jun 4, 2013 at 4:36 PM, Stephen Warren swarren@wwwdotorg.org wrote:
That seems like a reasonable way for the code to work. However, you'd need to modify common/env_mmc.c:init_mmc_for_env() so that it saves off mmc->part_num before switching MMC partitions, so that fini_mmc_for_env() knows which partition to switch back to. Right now, it relies on the fact that mmc_switch_part() does not update mmc->part_num, and hence uses that value to save the previously selected partition ID.
Also, if you make this change, I think you can update common/cmd_mmc.c:do_mmcops(), since it will no longer need to update mmc->part_num after a successful switch.
I understood your second suggestion and did the changes below, but I am not sure on the first one regarding the change you proposed inside init_mmc_for_env().
In env_mmc.c, you'll want something like:
+#ifdef CONFIG_SYS_MMC_ENV_PART +static char orig_part_num; +#ifdef CONFIG_SYS_MMC_ENV_PART
static int init_mmc_for_env(struct mmc *mmc) ... #ifdef CONFIG_SYS_MMC_ENV_PART + orig_part_num = mmc->part_num; if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num) { if (mmc_switch_part(CONFIG_SYS_MMC_ENV_DEV, CONFIG_SYS_MMC_ENV_PART)) { puts("MMC partition switch failed\n"); return -1; } } #endif ... static void fini_mmc_for_env(struct mmc *mmc) { #ifdef CONFIG_SYS_MMC_ENV_PART - if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num) + if (mmc->part_num != orig_part_num) mmc_switch_part(CONFIG_SYS_MMC_ENV_DEV, - mmc->part_num); + orig_part_num); #endif }
On Tue, Jun 4, 2013 at 7:12 PM, Stephen Warren swarren@wwwdotorg.org wrote:
In env_mmc.c, you'll want something like:
Thanks for the patch, but when I add these changes on top of my patch it results in the original error:
U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed U-Boot >
On 06/04/2013 05:09 PM, Fabio Estevam wrote:
On Tue, Jun 4, 2013 at 7:12 PM, Stephen Warren swarren@wwwdotorg.org wrote:
In env_mmc.c, you'll want something like:
Thanks for the patch, but when I add these changes on top of my patch it results in the original error:
Of course; with that patch applied, there is no effective difference in the code - you've just cleaned it up to have the MMC core manage mmc->part_num, rather than requiring all callers to update it themselves.
U-Boot > save Saving Environment to MMC... Writing to MMC(1)... done U-Boot > save Saving Environment to MMC... MMC partition switch failed U-Boot >
I have no idea why that happens. You'll simply have to debug the code. Do you have CONFIG_SYS_MMC_ENV_PART set? I wasn't aware anyone else used it, besides Tegra.
On Tue, Jun 4, 2013 at 8:30 PM, Stephen Warren swarren@wwwdotorg.org wrote:
Do you have CONFIG_SYS_MMC_ENV_PART set? I wasn't aware anyone else used it, besides Tegra.
Yes, this is the issue. CONFIG_SYS_MMC_ENV_PART is used incorrectly on this board.
Will update its config file.
On Tue, Jun 4, 2013 at 7:12 PM, Stephen Warren swarren@wwwdotorg.org wrote:
static void fini_mmc_for_env(struct mmc *mmc) { #ifdef CONFIG_SYS_MMC_ENV_PART
if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num)
if (mmc->part_num != orig_part_num) mmc_switch_part(CONFIG_SYS_MMC_ENV_DEV,
mmc->part_num);
orig_part_num);
If I keep the original 'mmc->part_num' here, then it works.
On 06/04/2013 05:16 PM, Fabio Estevam wrote:
On Tue, Jun 4, 2013 at 7:12 PM, Stephen Warren swarren@wwwdotorg.org wrote:
static void fini_mmc_for_env(struct mmc *mmc) { #ifdef CONFIG_SYS_MMC_ENV_PART
if (CONFIG_SYS_MMC_ENV_PART != mmc->part_num)
if (mmc->part_num != orig_part_num) mmc_switch_part(CONFIG_SYS_MMC_ENV_DEV,
mmc->part_num);
orig_part_num);If I keep the original 'mmc->part_num' here, then it works.
It doesn't "work", it just hides the problem. By passing mmc->part_num here, you're passing the partition that's already/currently selected rather than restoring the original value. Selecting it again is a no-op; IIRC the MMC core explicitly checks for this condition and immediately returns without touching the HW.
participants (3)
-
Fabio Estevam -
Fabio Estevam -
Stephen Warren