On Sun, 15 Apr 2012, Sujit Reddy Thumma wrote:
> Hi Nicolas,
>
> >
> > Commit 06e8935feb "optimized SDIO IRQ handling for single irq"
> > introduced some spurious calls to SDIO function interrupt handlers,
> > such as when the SDIO IRQ thread is started, or the safety check
> > performed upon a system resume. Let's add a flag to perform the
> > optimization only when a real interrupt is signaled by the host
> > driver and we know there is no point confirming it.
> >
>
> Thanks for putting up formal patch.
>
> > Reported-by: Sujit Reddy Thumma <sthumma@xxxxxxxxxxxxxx>
> > Signed-off-by: Nicolas Pitre <nico@xxxxxxxxxx>
> > Cc: stable@xxxxxxxxxx
> >
> > diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
> > index f573e7f9f7..3d8ceb4084 100644
> > --- a/drivers/mmc/core/sdio_irq.c
> > +++ b/drivers/mmc/core/sdio_irq.c
> > @@ -28,18 +28,20 @@
> >
> > #include "sdio_ops.h"
> >
> > -static int process_sdio_pending_irqs(struct mmc_card *card)
> > +static int process_sdio_pending_irqs(struct mmc_host *host)
> > {
> > + struct mmc_card *card = host->card;
> > int i, ret, count;
> > unsigned char pending;
> > struct sdio_func *func;
> >
> > /*
> > * Optimization, if there is only 1 function interrupt registered
> > - * call irq handler directly
> > + * and we know an IRQ was signaled then call irq handler directly.
> > + * Otherwise do the full probe.
> > */
> > func = card->sdio_single_irq;
> > - if (func) {
> > + if (func && host->sdio_irq_pending) {
> > func->irq_handler(func);
> > return 1;
> > }
> > @@ -116,7 +118,8 @@ static int sdio_irq_thread(void *_host)
> > ret = __mmc_claim_host(host, &host->sdio_irq_thread_abort);
> > if (ret)
> > break;
> > - ret = process_sdio_pending_irqs(host->card);
> > + ret = process_sdio_pending_irqs(host);
> > + host->sdio_irq_pending = false;
> > mmc_release_host(host);
> >
> > /*
> > diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> > index ee2b0363c0..557aa4cd66 100644
> > --- a/include/linux/mmc/host.h
> > +++ b/include/linux/mmc/host.h
> > @@ -323,6 +323,7 @@ struct mmc_host {
> >
> > unsigned int sdio_irqs;
> > struct task_struct *sdio_irq_thread;
> > + bool sdio_irq_pending;
> > atomic_t sdio_irq_thread_abort;
> >
> > mmc_pm_flag_t pm_flags; /* requested pm features */
> > @@ -378,6 +379,7 @@ extern int mmc_cache_ctrl(struct mmc_host *, u8);
> > static inline void mmc_signal_sdio_irq(struct mmc_host *host)
> > {
> > host->ops->enable_sdio_irq(host, 0);
> > + host->sdio_irq_pending = true;
> > wake_up_process(host->sdio_irq_thread);
> > }
>
> In this case probably we need to add the following:
> @@ -946,8 +946,11 @@ static int mmc_sdio_resume(struct mmc_host *host)
> }
> }
>
> - if (!err && host->sdio_irqs)
> - mmc_signal_sdio_irq(host);
> + if (!err && host->sdio_irqs) {
> + host->ops->enable_sdio_irq(host, 0);
> + wake_up_process(host->sdio_irq_thread);
> + }
The call to enable_sdio_irq() is probably redundant. Only
wake_up_process() should be sufficient.
Nicolas
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