Re: [PATCH v2 1/1] mmc: core: hs200 fixes

[Chris Ball <cjb@laptop.org>]

Hi,

On Tue, Mar 06 2012, Girish K S wrote:
> On 6 March 2012 17:59, Subhash Jadavani <subhashj@codeaurora.org> wrote:
>> This patch fixes following issues when HS200 is enabled:
>>
>> 1. If executing_tuning() host ops is called without mmc_host_clk_hold(),
>>   card clocks might get turned off (if MMC_CLK_GATING is enabled)
>>   while execute_tuning() is in progress. So this patch makes sure
>>   that execute_tuning() is called with mmc_host_clk_hold().
>>
>> 2. If host timing mode is set to HS200 mode, there should not be
>>   any communication with the card until execute_tuning() is completed.
>>   But there is a chance that CMD6 might be sent to enable set HPI_EN
>>   (of HPI_MGMT field in EXT_CSD) before execute_tuning() is called.
>>   So this patch moves this operation after execute_tuning() is completed.
>>
>> Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
>> ---
>>  drivers/mmc/core/mmc.c |   38 +++++++++++++++++++++-----------------
>>  1 files changed, 21 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>> index a480663..d36d2c4 100644
>> --- a/drivers/mmc/core/mmc.c
>> +++ b/drivers/mmc/core/mmc.c
>> @@ -1030,22 +1030,6 @@ static int mmc_init_card(struct mmc_host
>> *host, u32 ocr,
>>        }
>>
>>        /*
>> -        * Enable HPI feature (if supported)
>> -        */
>> -       if (card->ext_csd.hpi) {
>> -               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> -                       EXT_CSD_HPI_MGMT, 1, 0);
>> -               if (err && err != -EBADMSG)
>> -                       goto free_card;
>> -               if (err) {
>> -                       pr_warning("%s: Enabling HPI failed\n",
>> -                                  mmc_hostname(card->host));
>> -                       err = 0;
>> -               } else
>> -                       card->ext_csd.hpi_en = 1;
>> -       }
>> -
>> -       /*
>>         * Compute bus speed.
>>         */
>>        max_dtr = (unsigned int)-1;
>> @@ -1094,9 +1078,12 @@ static int mmc_init_card(struct mmc_host
>> *host, u32 ocr,
>>                 * 4. execute tuning for HS200
>>                 */
>>                if ((host->caps2 & MMC_CAP2_HS200) &&
>> -                   card->host->ops->execute_tuning)
>> +                   card->host->ops->execute_tuning) {
>> +                       mmc_host_clk_hold(card->host);
>>                        err = card->host->ops->execute_tuning(card->host,
>>                                MMC_SEND_TUNING_BLOCK_HS200);
>> +                       mmc_host_clk_release(card->host);
>> +               }
>>                if (err) {
>>                        pr_warning("%s: tuning execution failed\n",
>>                                   mmc_hostname(card->host));
>> @@ -1216,6 +1203,23 @@ static int mmc_init_card(struct mmc_host
>> *host, u32 ocr,
>>        }
>>
>>        /*
>> +        * Enable HPI feature (if supported)
>> +        */
>> +       if (card->ext_csd.hpi) {
>> +               err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
>> +                               EXT_CSD_HPI_MGMT, 1,
>> +                               card->ext_csd.generic_cmd6_time);
>> +               if (err && err != -EBADMSG)
>> +                       goto free_card;
>> +               if (err) {
>> +                       pr_warning("%s: Enabling HPI failed\n",
>> +                                  mmc_hostname(card->host));
>> +                       err = 0;
>> +               } else
>> +                       card->ext_csd.hpi_en = 1;
>> +       }
>> +
>> +       /*
>>         * If cache size is higher than 0, this indicates
>>         * the existence of cache and it can be turned on.
>>         */
>
> Reviewed-By: girish.shivananjappa@linaro.org

Thanks, pushed to mmc-next for 3.4.

- Chris.
-- 
Chris Ball   <cjb@laptop.org>   <http://printf.net/>
One Laptop Per Child