[U-Boot] [PATCH] cmd_mmc.c: check mmc_init() during mmc dev

[U-Boot] [PATCH] cmd_mmc.c: check mmc_init() during mmc dev

[Bryan Wu]

mmc dev ${devnum} will return 0 as success even if there is no card
inserted. Booting script like tegra-common-post.h will call mmc dev
${devnum} to check the mmc device status, it always return 0 even if
mmc_init() fails.

Check mmc_init() return value let mmc dev command return failure
when mmc_init() fails.

Signed-off-by: Bryan Wu <pengw@nvidia.com>
---
 common/cmd_mmc.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c
index c1916c9..56dcf48 100644
--- a/common/cmd_mmc.c
+++ b/common/cmd_mmc.c
@@ -195,6 +195,7 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	} else if (strcmp(argv[1], "dev") == 0) {
 		int dev, part = -1;
 		struct mmc *mmc;
+		int ret;
 
 		if (argc == 2)
 			dev = curr_device;
@@ -217,7 +218,10 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 			return 1;
 		}
 
-		mmc_init(mmc);
+		ret = mmc_init(mmc);
+		if (ret)
+			return ret;
+
 		if (part != -1) {
 			int ret;
 			if (mmc->part_config == MMCPART_NOAVAILABLE) {
-- 
1.7.11.4

[U-Boot] [PATCH] cmd_mmc.c: check mmc_init() during mmc dev

[Stephen Warren]

On 05/19/2014 06:17 PM, Bryan Wu wrote:
> mmc dev ${devnum} will return 0 as success even if there is no card
> inserted. Booting script like tegra-common-post.h will call mmc dev
> ${devnum} to check the mmc device status, it always return 0 even if
> mmc_init() fails.
> 
> Check mmc_init() return value let mmc dev command return failure
> when mmc_init() fails.

You probably want to Cc the MMC maintainer.

> diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c

> @@ -195,6 +195,7 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>  	} else if (strcmp(argv[1], "dev") == 0) {
>  		int dev, part = -1;
>  		struct mmc *mmc;
> +		int ret;

The latest u-boot.git master branch already declares ret a couple lines
above. Hence, this patch doesn't compile.

> -		mmc_init(mmc);
> +		ret = mmc_init(mmc);
> +		if (ret)
> +			return ret;

I know that I said off-list to return ret here, but it actually looks
like U-Boot commands must not return arbitrary values, but rather must
return 0, 1, or CMD_RET_USAGE. The current code prints the following on
failure:

Tegra124 (Jetson TK1) # mmc dev 1
MMC: no card present
exit not allowed from main input shell.

I'll send a V2 patch with these fixed.

[U-Boot] [PATCH] cmd_mmc.c: check mmc_init() during mmc dev

[Bryan Wu]

On Tue, May 20, 2014 at 9:55 AM, Stephen Warren <swarren@wwwdotorg.org> wrote:
> On 05/19/2014 06:17 PM, Bryan Wu wrote:
>> mmc dev ${devnum} will return 0 as success even if there is no card
>> inserted. Booting script like tegra-common-post.h will call mmc dev
>> ${devnum} to check the mmc device status, it always return 0 even if
>> mmc_init() fails.
>>
>> Check mmc_init() return value let mmc dev command return failure
>> when mmc_init() fails.
>
> You probably want to Cc the MMC maintainer.
>
>> diff --git a/common/cmd_mmc.c b/common/cmd_mmc.c
>
>> @@ -195,6 +195,7 @@ static int do_mmcops(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
>>       } else if (strcmp(argv[1], "dev") == 0) {
>>               int dev, part = -1;
>>               struct mmc *mmc;
>> +             int ret;
>
> The latest u-boot.git master branch already declares ret a couple lines
> above. Hence, this patch doesn't compile.
>
>> -             mmc_init(mmc);
>> +             ret = mmc_init(mmc);
>> +             if (ret)
>> +                     return ret;
>
> I know that I said off-list to return ret here, but it actually looks
> like U-Boot commands must not return arbitrary values, but rather must
> return 0, 1, or CMD_RET_USAGE. The current code prints the following on
> failure:
>
> Tegra124 (Jetson TK1) # mmc dev 1
> MMC: no card present
> exit not allowed from main input shell.
>
> I'll send a V2 patch with these fixed.


Thanks for pushing this. I will update downstream version.

-Bryan