Re: [PATCH] mmc: mmc: fix check on mmc_select_bus_width return value

[Dan O'Donovan <dan@emutex.com>]

On 06/01/2016 01:43 PM, Jaehoon Chung wrote:
> On 06/01/2016 09:17 PM, Dan O'Donovan wrote:
>> This fixes a bug introduced by commit 287980e49ffc ("remove lots of
>> IS_ERR_VALUE abuses").  mmc_select_bus_width can return positive
>> integer values upon success, so the (!err) check is incorrect here.
>> This causes mmc initialisation failure, and subsequently boot
>> failure, on some platforms.
> Refer to below patch.
>
> https://patchwork.kernel.org/patch/9139673/
>
> Best Regards,
> Jaehoon Chung
Ah, sorry I missed that.  Glad to see a fix is on the way already.  Please disregard my patch.  Thanks!
>
>> Signed-off-by: Dan O'Donovan <dan@emutex.com>
>> ---
>>  drivers/mmc/core/mmc.c | 4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index c984321..5d438ad 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -1276,7 +1276,7 @@ static int mmc_select_hs200(struct mmc_card *card)
>>  	 * switch to HS200 mode if bus width is set successfully.
>>  	 */
>>  	err = mmc_select_bus_width(card);
>> -	if (!err) {
>> +	if (err >= 0) {
>>  		val = EXT_CSD_TIMING_HS200 |
>>  		      card->drive_strength << EXT_CSD_DRV_STR_SHIFT;
>>  		err = __mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> @@ -1583,7 +1583,7 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
>>  	} else if (mmc_card_hs(card)) {
>>  		/* Select the desired bus width optionally */
>>  		err = mmc_select_bus_width(card);
>> -		if (!err) {
>> +		if (err >= 0) {
>>  			err = mmc_select_hs_ddr(card);
>>  			if (err)
>>  				goto free_card;
>>