On 27 January 2014 11:46, Adrian Hunter <[email protected]> wrote:
> 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.
>
Agree!
>>
>> 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
Will fix in v2, thanks!
>
>>
>> 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
>>
>>
>
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