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authorNicolas Pitre <nicolas.pitre@linaro.org>2012-04-16 19:16:54 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-06-01 15:15:53 +0800
commit591c8732fb7d28b5a5d1299bf8822f3880efaa47 (patch)
tree532cc152d2159f2d13b4d303ed4899c63d556fe3
parentx86/mce: Fix check for processor context when machine check was taken. (diff)
downloadlinux-stable-591c8732fb7d28b5a5d1299bf8822f3880efaa47.tar.xz
linux-stable-591c8732fb7d28b5a5d1299bf8822f3880efaa47.zip
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>
-rw-r--r--drivers/mmc/core/sdio.c2
-rw-r--r--drivers/mmc/core/sdio_irq.c11
-rw-r--r--include/linux/mmc/host.h2
3 files changed, 10 insertions, 5 deletions
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 2c7c83f832d2..13d0e95380ab 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -947,7 +947,7 @@ 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 f573e7f9f740..3d8ceb4084de 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 ee2b0363c040..557aa4cd660f 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);
}