mmc: sdio: avoid spurious calls to interrupt handlers

commit bbbc4c4d8c5face097d695f9bf3a39647ba6b7e7 upstream.

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.

Reported-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 3ab565e32a6aca624d6f462879a0c19b7cae7697..558a49564b76ce535d7a45f0a589ce5bb47ea21e 100644 (file)
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -663,7 +663,7 @@ static int mmc_sdio_resume(struct mmc_host *host)
        }
 
        if (!err && host->sdio_irqs)
-               mmc_signal_sdio_irq(host);
+               wake_up_process(host->sdio_irq_thread);
        mmc_release_host(host);
 
        /*

diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index 68f81b9ee0fbe4eb10c962b0ddb088ee11f8e213..9dd046263d74d6f25770257b6a4586a4f93e24b4 100644 (file)
--- 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 a3ac9c48e5de60dc71fe71f3eb5d067e315ac4fb..deb6282e440ba84769512549d71a5f08fff15c52 100644 (file)
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -303,6 +303,7 @@ 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 */
@@ -356,6 +357,7 @@ 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);
 }