On 19/07/16 14:57, Ulf Hansson wrote:
> On 13 June 2016 at 10:54, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
>> When mmc host HW supports busy signalling (using R1B as response), We
>> shouldn't use 'host->max_busy_timeout' as the limitation when deciding
>> the max discard sectors that we tell the generic BLOCK layer about.
>> Instead, we should pick one preferred erase size as the max discard
>> sectors.
>>
>> If the host controller supports busy signalling and the timeout for
>> the erase operation does not exceed the max_busy_timeout, we should
>> use R1B response. Or we need to prevent the host from doing hw busy
>> detection, which is done by converting to a R1 response instead.
>>
>> Changes since v1:
>> - Remove the 'MMC_CAP_WAIT_WHILE_BUSY' flag checking when deciding
>> the max discard sectors.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>> ---
>> drivers/mmc/core/core.c | 47 +++++++++++++++++++++++++++++++++++++++--------
>> 1 file changed, 39 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index 8b4dfd4..edd43b1 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -2060,7 +2060,7 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
>> unsigned int to, unsigned int arg)
>> {
>> struct mmc_command cmd = {0};
>> - unsigned int qty = 0;
>> + unsigned int qty = 0, busy_timeout = 0;
>> unsigned long timeout;
>> int err;
>>
>> @@ -2128,8 +2128,23 @@ static int mmc_do_erase(struct mmc_card *card, unsigned int from,
>> memset(&cmd, 0, sizeof(struct mmc_command));
>> cmd.opcode = MMC_ERASE;
>> cmd.arg = arg;
>> - cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
>> - cmd.busy_timeout = mmc_erase_timeout(card, arg, qty);
>> + busy_timeout = mmc_erase_timeout(card, arg, qty);
>> + /*
>> + * If the host controller supports busy signalling and the timeout for
>> + * the erase operation does not exceed the max_busy_timeout, we should
>> + * use R1B response. Or we need to prevent the host from doing hw busy
>> + * detection, which is done by converting to a R1 response instead.
>> + */
>> + if ((card->host->max_busy_timeout &&
>> + busy_timeout > card->host->max_busy_timeout) ||
>> + !(card->host->caps & MMC_CAP_WAIT_WHILE_BUSY)) {
>
> sdhci uses the max_busy_timeout, but doesn't always use MMC_CAP_WAIT_WHILE_BUSY.
> I have probably asked Adrian about this before, but right now I can't
> recall why this is the case.
Unfortunately, just because a driver does not set MMC_CAP_WAIT_WHILE_BUSY
does not mean it does not have the capability. So we still want to set the
correct timeout and maximum timeout.
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