From 5d0f058eaa125df9a3b53ec3cbe9c385acaee959 Mon Sep 17 00:00:00 2001
From: Jun Nie <njun@marvell.com>
Date: Fri, 12 Nov 2010 19:43:49 +0800
Subject: [PATCH] mmc: check SDIO card wake up during suspending
It is possible that SDIO card issue card interrupt to wake up
system just after SDIO func driver and SDIO card firmware commit
suspend state, while system is still in suspending process and
mmc interrupt is not release yet.
Interrupt storm may happen if func driver does not notify firmware
to clear the wake up source. If func driver issue SDIO bus transaction
to have firmware clear the source and driver try to handle the wake
up event, system may enter suspend before all transaction done.
In this case, SDIO card will not enter lower power mode never. But
system can not be wake up for only card insert/remove/interrupt irq are
listed in wake up source in SD spec. Data/command done irq can
not wake up system.
This patch check SDIO card interrupt and stop system suspend if there
are card interrupt after func driver suspend.
Signed-off-by: Jun Nie <njun@marvell.com>
---
drivers/mmc/core/sdio.c | 14 ++++++++++++++
drivers/mmc/core/sdio_irq.c | 5 +++++
drivers/mmc/host/sdhci.c | 14 +++++++++++++-
include/linux/mmc/card.h | 2 ++
include/linux/mmc/sdio_func.h | 2 ++
5 files changed, 36 insertions(+), 1 deletions(-)
@@ -584,6 +584,14 @@ static int mmc_sdio_suspend(struct mmc_host *host)
for (i = 0; i < host->card->sdio_funcs; i++) {
struct sdio_func *func = host->card->sdio_func[i];
+ /* cancel suspend once we detect external wake up source */
+ if (host->card->pending_interrupt) {
+ host->card->pending_interrupt = 0;
+ err = -EBUSY;
+ printk(KERN_ALERT "%s: wake up event after device suspended\n",
+ mmc_hostname(host));
+ break;
+ }
if (func && sdio_func_present(func) && func->dev.driver) {
const struct dev_pm_ops *pmops = func->dev.driver->pm;
if (!pmops || !pmops->suspend || !pmops->resume) {
@@ -593,10 +601,15 @@ static int mmc_sdio_suspend(struct mmc_host *host)
err = pmops->suspend(&func->dev);
if (err)
break;
+ else
+ /* It is prefer that func driver set it in its
+ suspend function with mmc_claim_host */
+ func->suspended = true;
}
}
while (err && --i >= 0) {
struct sdio_func *func = host->card->sdio_func[i];
+ func->suspended = false;
if (func && sdio_func_present(func) && func->dev.driver) {
const struct dev_pm_ops *pmops = func->dev.driver->pm;
pmops->resume(&func->dev);
@@ -639,6 +652,7 @@ static int mmc_sdio_resume(struct mmc_host *host)
*/
for (i = 0; !err && i < host->card->sdio_funcs; i++) {
struct sdio_func *func = host->card->sdio_func[i];
+ func->suspended = false;
if (func && sdio_func_present(func) && func->dev.driver) {
const struct dev_pm_ops *pmops = func->dev.driver->pm;
err = pmops->resume(&func->dev);
@@ -49,6 +49,11 @@ static int process_sdio_pending_irqs(struct mmc_card *card)
mmc_card_id(card));
ret = -EINVAL;
} else if (func->irq_handler) {
+ if (func->suspended) {
+ card->pending_interrupt = true;
+ printk(KERN_WARNING "%s: IRQ that arrives in suspend mode"
+ " mode\n", sdio_func_id(func));
+ }
func->irq_handler(func);
count++;
} else {
@@ -24,6 +24,7 @@
#include <linux/leds.h>
#include <linux/mmc/host.h>
+#include <linux/mmc/card.h>
#include "sdhci.h"
@@ -1631,7 +1632,7 @@ out:
int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
{
- int ret;
+ int ret = 0;
sdhci_disable_card_detection(host);
@@ -1644,6 +1645,14 @@ int sdhci_suspend_host(struct sdhci_host *host, pm_message_t state)
if (host->vmmc)
ret = regulator_disable(host->vmmc);
+ if (host->mmc->card && host->mmc->card->pending_interrupt) {
+ DBG("*** %s wake up event after suspend, resuming to handle it\n",
+ mmc_hostname(host->mmc));
+ host->mmc->card->pending_interrupt = 0;
+ sdhci_resume_host(host);
+ ret = -EBUSY;
+ }
+
return ret;
}
@@ -1659,6 +1668,9 @@ int sdhci_resume_host(struct sdhci_host *host)
return ret;
}
+ if (host->mmc->card && host->mmc->card->pending_interrupt)
+ host->mmc->card->pending_interrupt = 0;
+
if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
if (host->ops->enable_dma)
@@ -146,6 +146,8 @@ struct mmc_card {
struct sdio_func_tuple *tuples; /* unknown common tuples */
struct dentry *debugfs_root;
+ /* external interrupt arrived after sdio function suspended */
+ u32 pending_interrupt;
};
#define mmc_card_mmc(c) ((c)->type == MMC_TYPE_MMC)
@@ -59,6 +59,8 @@ struct sdio_func {
const char **info; /* info strings */
struct sdio_func_tuple *tuples;
+
+ int suspended; /* SDIO function driver state */
};
#define sdio_func_present(f) ((f)->state & SDIO_STATE_PRESENT)
--
1.7.0.4