[U-Boot] [PATCH] mmc: add host_caps checking avoid switch card improperly
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com --- drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..ce34d05 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
+ /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) || + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
On Thu, Nov 17, 2011 at 3:31 AM, Macpaul Lin macpaul@andestech.com wrote:
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com
drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..ce34d05 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
- /*
- * If the host doesn't support SD_HIGHSPEED, do not switch card to
- * HIGHSPEED mode even if the card support SD_HIGHSPPED.
- * This can avoid furthur problem when the card runs in different
- * mode between the host.
- */
- if (!((mmc->host_caps & MMC_MODE_HS_52MHz) ||
- (mmc->host_caps & MMC_MODE_HS)))
- return 0;
Isn't this the wrong logic? It seems like you don't want to switch unless both support high speed. But this logic says to switch if either one does.
Shouldn't it be:
if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && (mmc->host_caps & MMC_MODE_HS))) return 0;
?
Andy
err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
1.7.3.5
Hi Andy,
2011/11/26 Andy Fleming afleming@gmail.com
On Thu, Nov 17, 2011 at 3:31 AM, Macpaul Lin macpaul@andestech.com wrote:
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
if (!((mmc->host_caps & MMC_MODE_HS_52MHz) ||(mmc->host_caps & MMC_MODE_HS)))return 0;
I wrote this is because I've thought that SD cards usually work at 50MHz when they under high speed mode (MMC_MODE_HS), and MMC cards usually work at 52MHz when they are under high speed mode. I'm not sure if one controller support HS_52MHz for MMC cards will definitely support SD cards under 50MHz. If I'm wrong for the above please correct me.
Hence I wrote this to force them working under low speed to avoid problem occur.
But I think you're correct, we should use "&&" logic here until there is really a problem for the unbelievable situation I mentioned above that happened. :-p
Isn't this the wrong logic? It seems like you don't want to switch unless both support high speed. But this logic says to switch if either one does.
Shouldn't it be:
if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && (mmc->host_caps & MMC_MODE_HS))) return 0;
?
I'll send patch v2 by using your logic later. Thanks!
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com --- Changes for v2: - Replace OR logic by AND logic; switch to high speed if controller support one of the high speed mode.
drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..98abf1c 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
+ /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com --- Changes for v2: - Replace OR logic by AND logic; switch to high speed if controller support one of the high speed mode.
drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..98abf1c 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
+ /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
Hi Andy
2011/11/28 Macpaul Lin macpaul@andestech.com
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com
Sorry for sending these multiple mails. The IT department of my company has set the mail server with incorrect routing parameters.
Please drop these multiple mails which are the same. I'll delete them in patchworks and left the only one patch v2 of this patch which should be correct.
Dear Macpaul Lin,
In message CACCg+XOTFWB8jrXsg4Z+o4eAV3b9iaEr64_=+OMZNs+MaJ+LAg@mail.gmail.com you wrote:
Please drop these multiple mails which are the same. I'll delete them in patchworks and left the only one patch v2 of this patch which should be correct.
But you've sent a V3, too ???
Best regards,
Wolfgang Denk
Hi Andy and Wolfgang,
2011/11/28 Wolfgang Denk wd@denx.de
Dear Macpaul Lin,
In message <CACCg+XOTFWB8jrXsg4Z+o4eAV3b9iaEr64_=+ OMZNs+MaJ+LAg@mail.gmail.com> you wrote:
Please drop these multiple mails which are the same. I'll delete them in patchworks and left the only one patch v2 of this
patch
which should be correct.
But you've sent a V3, too ???
Best regards,
Wolfgang Denk
I've send the several patches at that time I didn't know the mail server has problem. At that time I've send both correct and wrong patch v2 when I'm retrying hence I send v3 later. For the clarify, I'll send a new v4 while the contents remain the same. Sorry for making problems. Thanks!
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com --- Changes for v2: - Replace OR logic by AND logic; switch to high speed if controller support one of the high speed mode. Changes for v3: - Correct the incorrect patch format. Changes for v4: - Update patch version number due to inappropiate message flooding by Andes's SMTP server.
drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..98abf1c 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
+ /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
On Mon, Nov 28, 2011 at 8:31 PM, Macpaul Lin macpaul@andestech.com wrote:
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com
Applied, thanks!
Andy
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com
Changes for v2: - Replace OR logic by AND logic; switch to high speed if controller support one of the high speed mode. --- drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..98abf1c 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
+ /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
Add a host capability checking to avoid the mmc stack switch the card to HIGHSPEED mode when the card supports HIGHSPEED while the host doesn't.
This patch avoid furthur transaction problem when the mmc/sd card runs different mode to the host.
Signed-off-by: Macpaul Lin macpaul@andestech.com --- Changes for v2: - Replace OR logic by AND logic; switch to high speed if controller support one of the high speed mode. Changes for v3: - Correct the incorrect patch format.
drivers/mmc/mmc.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index 21665ec..98abf1c 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -785,6 +785,16 @@ retry_scr: if (!(__be32_to_cpu(switch_status[3]) & SD_HIGHSPEED_SUPPORTED)) return 0;
+ /* + * If the host doesn't support SD_HIGHSPEED, do not switch card to + * HIGHSPEED mode even if the card support SD_HIGHSPPED. + * This can avoid furthur problem when the card runs in different + * mode between the host. + */ + if (!((mmc->host_caps & MMC_MODE_HS_52MHz) && + (mmc->host_caps & MMC_MODE_HS))) + return 0; + err = sd_switch(mmc, SD_SWITCH_SWITCH, 0, 1, (u8 *)switch_status);
if (err)
participants (4)
-
Andy Fleming -
Macpaul Lin -
Macpaul Lin -
Wolfgang Denk