On 23/01/14 16:26, Ulf Hansson wrote:
> On 23 January 2014 11:23, Adrian Hunter <[email protected]> wrote:
>> On 22/01/14 17:00, Ulf Hansson wrote:
>>> When sending the sleep command for host drivers supporting
>>> MMC_CAP_WAIT_WHILE_BUSY, we need to confirm that max_busy_timeout is
>>> big enough comparing to the sleep timeout specified from card's
>>> EXT_CSD. If this isn't case, we use a R1 response instead of R1B and
>>> fallback to use a delay instead.
>>>
>>> Do note that a max_busy_timeout set to zero by the host, is interpreted
>>> as it can cope with whatever timeout the mmc core provides it with.
>>>
>>> Signed-off-by: Ulf Hansson <[email protected]>
>>> ---
>>> drivers/mmc/core/mmc.c | 19 ++++++++++++++++---
>>> 1 file changed, 16 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>>> index 897fdd1..32e1546 100644
>>> --- a/drivers/mmc/core/mmc.c
>>> +++ b/drivers/mmc/core/mmc.c
>>> @@ -1359,6 +1359,8 @@ static int mmc_sleep(struct mmc_host *host)
>>> {
>>> struct mmc_command cmd = {0};
>>> struct mmc_card *card = host->card;
>>> + unsigned int timeout_ms = DIV_ROUND_UP(card->ext_csd.sa_timeout,
>>> 10000);
>>> + unsigned int max_busy_timeout;
>>> int err;
>>>
>>> if (host->caps2 & MMC_CAP2_NO_SLEEP_CMD)
>>> @@ -1372,7 +1374,18 @@ static int mmc_sleep(struct mmc_host *host)
>>> cmd.arg = card->rca << 16;
>>> cmd.arg |= 1 << 15;
>>>
>>> - cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
>>> + /* We interpret unspecified timeouts as the host can cope with all. */
>>> + max_busy_timeout = host->max_busy_timeout ?
>>> + host->max_busy_timeout : timeout_ms;
>>> +
>>> + if ((host->caps & MMC_CAP_WAIT_WHILE_BUSY) &&
>>> + (timeout_ms <= max_busy_timeout)) {
>>> + cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
>>> + cmd.busy_timeout = timeout_ms;
>>> + } else {
>>> + cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
>>> + }
>>
>> I do not see why this is related to MMC_CAP_WAIT_WHILE_BUSY.
>> Why not just:
>
> Before I do any update, we need to decide what host->max_busy_timeout
> of zero means. Please see the response in the other patch in this
> patchset.
Unless you want to change all the host controller drivers, zero means
don't know.
>
> I see that my patch for the mmc_switch function, maintain the R1B for
> host not supporting MMC_CAP_WAIT_WHILE_BUSY, but this one for sleep
> doesn't. :-) We should align the behaviour.
>
>
>>
>> if (host->max_busy_timeout && timeout_ms > host->max_busy_timeout) {
>> cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
>> } else {
>> cmd.flags = MMC_RSP_R1B | MMC_CMD_AC;
>> cmd.busy_timeout = timeout_ms;
>> }
>
> So here your suggestion will mean you would like to keep R1B for hosts
> not supporting MMC_CAP_WAIT_WHILE_BUSY. This opposite of what you
> proposed for the mmc_switch. :-)
I suggested:
if (timeout_ms && host->max_busy_timeout && timeout_ms >
host->max_busy_timeout)
use_r1b_resp = false;
(without modifying timeout_ms) which wasn't related to MMC_CAP_WAIT_WHILE_BUSY
i.e. keeps R1B for hosts not supporting MMC_CAP_WAIT_WHILE_BUSY
>
> I suggest that we only use R1B when the host are able to handle busy
> detection in hw. If you think that is bad idea, please let me know.
>
>>
>>> +
>>> err = mmc_wait_for_cmd(host, &cmd, 0);
>>> if (err)
>>> return err;
>>> @@ -1383,8 +1396,8 @@ static int mmc_sleep(struct mmc_host *host)
>>> * SEND_STATUS command to poll the status because that command (and
>>> most
>>> * others) is invalid while the card sleeps.
>>> */
>>> - if (!(host->caps & MMC_CAP_WAIT_WHILE_BUSY))
>>> - mmc_delay(DIV_ROUND_UP(card->ext_csd.sa_timeout, 10000));
>>> + if (!cmd.busy_timeout)
>>> + mmc_delay(timeout_ms);
>>
>> And this becomes:
>>
>> if (!cmd.busy_timeout || !(host->caps & MMC_CAP_WAIT_WHILE_BUSY))
>> mmc_delay(timeout_ms);
>>
>>>
>>> return err;
>>> }
>>>
>>
>
> Kind regards
> Uffe
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
