[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 at 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