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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

3 files changed, 10 insertions, 5 deletions

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index ac492ac974e..9b18b541659 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -665,7 +665,7 @@ 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 03ead028d2c..d58ae915337 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -27,18 +27,20 @@
 
 #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;
         }
@@ -115,7 +117,8 @@ 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 1ee4424462e..f8d1e741d80 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -267,6 +267,7 @@ 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 */
@@ -312,6 +313,7 @@ extern void mmc_request_done(struct mmc_host *, struct mmc_request *);
 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);
 }