On 19 November 2013 14:37, Andreas Fenkart <afenkart@xxxxxxxxx> wrote:
> Hi Ulf,
>
> 2013/11/19 Ulf Hansson <ulf.hansson@xxxxxxxxxx>:
>> On 18 November 2013 08:53, Andreas Fenkart <afenkart@xxxxxxxxx> wrote:
>
>>>
>>> +static irqreturn_t omap_hsmmc_cirq(int irq, void *dev_id)
>>> +{
>>> + struct omap_hsmmc_host *host = dev_id;
>>> + unsigned long flags;
>>> +
>>> + spin_lock_irqsave(&host->irq_lock, flags);
>>> + if (host->flags & HSMMC_CIRQ_GPIO_ENABLED) {
>>> + disable_irq_nosync(mmc_slot(host).sdio_irq);
>>> + host->flags &= ~HSMMC_CIRQ_GPIO_ENABLED;
>>> + }
>>> + spin_unlock_irqrestore(&host->irq_lock, flags);
>>> +
>>> + pm_request_resume(host->dev); /* no use counter */
>>
>> In the case were you are not waking up from system suspend, but from
>> runtime suspend, you likely want to signal the SDIO irq as soon as
>> possible. Then you should use mmc_signal_sdio_irq instead.
>
> That was my intention first as well, and previous patches worked that way.
> SDIO IRQ while in pm_suspend is a rare event, compard to SDIO irq
> while in pm_active state.
>
> cat /proc/interrupts
> CPU0
> 80: 68349 INTC 64 mmc0
> 236: 4352 GPIO 28 mmc0
>
> Here the Wifi module is just connected, not being pinged or iperf
> running. So the benefit will not be as big as you imagine.
You are right.
>
> On the other side the optimisations is not without problems, while in
> pm_suspend the functional clock is off and you must not access the
> registers of the module.
>
> But this is exactly whapt happens when you call mmc_signal_sdio_irq,
> it will call back into the drivers omap_hsmmc_enable_sdio_irq trying to
> disable the SDIO irq. So you must add special state machines there.
Yes, it will be somewhat complicated - I guess.
>
> After all it's doable but error prone, and I consider not worth the troubles
> for no noticeable speedup.
>
> Also have a look here, Balaji T K had a similar remark to yours
> http://www.spinics.net/lists/linux-omap/msg99832.html
Thanks, I should have looked that first. :-)
Kind regards
Ulf Hansson
>
>>
>> In the other case, when waking up from system suspend, you should be
>> able to completely rely on that the mmc_sdio_resume from the core
>> layer, will handle the IRQ.
>>
>> Kind regards
>> Ulf Hansson
>>
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