Hi,
On Friday 11 September 2015 07:29 PM, Ulf Hansson wrote:
> On 11 September 2015 at 15:22, Kishon Vijay Abraham I <kishon@xxxxxx> wrote:
>> Hi Ulf,
>>
>> On Friday 11 September 2015 06:11 PM, Ulf Hansson wrote:
>>> As mmc_claim_host() invokes pm_runtime_get_sync() for the mmc host device,
>>> it's important that the host is kept claimed for *all* accesses to it via
>>> the host_ops callbacks.
>>>
>>> In some code paths for SDIO, particularly related to the PM support,
>>> mmc_power_off|up() is invoked without keeping the host claimed. Let's fix
>>> these.
>>>
>>> Moreover, mmc_start|stop_host() also invokes mmc_power_off|up() without
>>> claiming the host, let's fix these as well.
>>>
>>> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
>>> ---
>>> drivers/mmc/core/core.c | 6 ++++++
>>> drivers/mmc/core/sdio.c | 20 +++++++++++++++-----
>>> 2 files changed, 21 insertions(+), 5 deletions(-)
>>>
>> .
>> .
>> <snip>
>> .
>> .
>>> int mmc_power_save_host(struct mmc_host *host)
>>> diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
>>> index b91abed..95bc101 100644
>>> --- a/drivers/mmc/core/sdio.c
>>> +++ b/drivers/mmc/core/sdio.c
>>> @@ -897,11 +897,10 @@ static int mmc_sdio_pre_suspend(struct mmc_host *host)
>>> */
>>> static int mmc_sdio_suspend(struct mmc_host *host)
>>> {
>>> - if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host)) {
>>> - mmc_claim_host(host);
>>> + mmc_claim_host(host);
>>> +
>>> + if (mmc_card_keep_power(host) && mmc_card_wake_sdio_irq(host))
>>> sdio_disable_wide(host->card);
>>> - mmc_release_host(host);
>>> - }
>>>
>>> if (!mmc_card_keep_power(host)) {
>>> mmc_power_off(host);
>>> @@ -910,6 +909,8 @@ static int mmc_sdio_suspend(struct mmc_host *host)
>>> mmc_retune_needed(host);
>>> }
>>>
>>> + mmc_release_host(host);
>>> +
>>> return 0;
>>> }
>>>
>>> @@ -1018,15 +1019,24 @@ out:
>>> static int mmc_sdio_runtime_suspend(struct mmc_host *host)
>>> {
>>> /* No references to the card, cut the power to it. */
>>> + mmc_claim_host(host);
>>> mmc_power_off(host);
>>> + mmc_release_host(host);
>>> +
>>> return 0;
>>> }
>>>
>>> static int mmc_sdio_runtime_resume(struct mmc_host *host)
>>> {
>>> + int ret;
>>> +
>>> /* Restore power and re-initialize. */
>>> + mmc_claim_host(host);
>>> mmc_power_up(host, host->card->ocr);
>>> - return mmc_sdio_power_restore(host);
>>> + ret = mmc_sdio_power_restore(host);
>>
>> IIUC, this will cause mmc_claim_host to be invoked twice since
>> mmc_sdio_power_restore also invokes mmc_claim_host. I'm not sure if this
>> will have undesired side effects.
>
> That's not a problem, mmc_claim_host() handles that. As long it's the
> same running context that tries to claim the host it will allow it.
Alright then.
You can add my
Acked-by: Kishon Vijay Abraham I <kishon@xxxxxx>
Cheers
Kishon
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
