| Message ID | 20190908101236.2802-6-ulf.hansson@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: core: PM fixes/improvements for SDIO IRQs | expand |
Hi, On Sun, Sep 8, 2019 at 3:12 AM Ulf Hansson <ulf.hansson@linaro.org> wrote: > > The sdio_irq_pending flag is used to let host drivers indicate that it has > signaled an IRQ. If that is the case and we only have a single SDIO func > that have claimed an SDIO IRQ, our assumption is that we can avoid reading > the SDIO_CCCR_INTx register and just call the SDIO func irq handler > immediately. This makes sense, but the flag is set/cleared in a somewhat > messy order, let's fix that up according to below. > > First, the flag is currently set in sdio_run_irqs(), which is executed as a > work that was scheduled from sdio_signal_irq(). To make it more implicit > that the host have signaled an IRQ, let's instead immediately set the flag > in sdio_signal_irq(). This also makes the behavior consistent with host > drivers that uses the legacy, mmc_signal_sdio_irq() API. This have no > functional impact, because we don't expect host drivers to call > sdio_signal_irq() until after the work (sdio_run_irqs()) have been executed > anyways. > > Second, currently we never clears the flag when using the sdio_run_irqs() > work, but only when using the sdio_irq_thread(). Let make the behavior s/Let/Let's > consistent, by moving the flag to be cleared inside the common > process_sdio_pending_irqs() function. Additionally, tweak the behavior of > the flag slightly, by avoiding to clear it unless we processed the SDIO > IRQ. The purpose with this at this point, is to keep the information about > whether there have been an SDIO IRQ signaled by the host, so at system > resume we can decide to process it without reading the SDIO_CCCR_INTx > register. > > Tested-by: Matthias Kaehlcke <mka@chromium.org> > Reviewed-by: Matthias Kaehlcke <mka@chromium.org> > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Changes in v2: > - Re-wrote changelog. > > --- > drivers/mmc/core/sdio_irq.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) Reviewed-by: Douglas Anderson <dianders@chromium.org>
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c index f75043266984..0962a4357d54 100644 --- a/drivers/mmc/core/sdio_irq.c +++ b/drivers/mmc/core/sdio_irq.c @@ -59,6 +59,7 @@ static int process_sdio_pending_irqs(struct mmc_host *host) { struct mmc_card *card = host->card; int i, ret, count; + bool sdio_irq_pending = host->sdio_irq_pending; unsigned char pending; struct sdio_func *func; @@ -66,13 +67,16 @@ static int process_sdio_pending_irqs(struct mmc_host *host) if (mmc_card_suspended(card)) return 0; + /* Clear the flag to indicate that we have processed the IRQ. */ + host->sdio_irq_pending = false; + /* * Optimization, if there is only 1 function interrupt registered * and we know an IRQ was signaled then call irq handler directly. * Otherwise do the full probe. */ func = card->sdio_single_irq; - if (func && host->sdio_irq_pending) { + if (func && sdio_irq_pending) { func->irq_handler(func); return 1; } @@ -110,7 +114,6 @@ static void sdio_run_irqs(struct mmc_host *host) { mmc_claim_host(host); if (host->sdio_irqs) { - host->sdio_irq_pending = true; process_sdio_pending_irqs(host); if (host->ops->ack_sdio_irq) host->ops->ack_sdio_irq(host); @@ -128,6 +131,7 @@ void sdio_irq_work(struct work_struct *work) void sdio_signal_irq(struct mmc_host *host) { + host->sdio_irq_pending = true; queue_delayed_work(system_wq, &host->sdio_irq_work, 0); } EXPORT_SYMBOL_GPL(sdio_signal_irq); @@ -173,7 +177,6 @@ static int sdio_irq_thread(void *_host) if (ret) break; ret = process_sdio_pending_irqs(host); - host->sdio_irq_pending = false; mmc_release_host(host); /*