[PATCH v2] MMC: fix all hangs related to mmc/sd card insert/removal during suspend/resume.
From: Maxim Levitsky
Date: Fri Jun 11 2010 - 15:20:11 EST
If you don't use CONFIG_MMC_UNSAFE_RESUME, card will now be removed
in pm notified while userspace is still running.
Thus it will be possible to sync it propely.
Card detect workqueue is now freezeable, therefore a card insert/removal event will
wait till userspace is unfrozen.
Tested with and without CONFIG_MMC_UNSAFE_RESUME with suspend and hibernate.
Signed-off-by: Maxim Levitsky <maximlevitsky@xxxxxxxxx>
---
drivers/mmc/core/core.c | 54 +++++++++++++++++++++++++++------------------
drivers/mmc/core/host.c | 6 +++++
include/linux/mmc/host.h | 3 ++
3 files changed, 41 insertions(+), 22 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 569e94d..0cba53a 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1259,26 +1259,11 @@ int mmc_suspend_host(struct mmc_host *host)
if (host->caps & MMC_CAP_DISABLE)
cancel_delayed_work(&host->disable);
- cancel_delayed_work(&host->detect);
- mmc_flush_scheduled_work();
mmc_bus_get(host);
if (host->bus_ops && !host->bus_dead) {
if (host->bus_ops->suspend)
err = host->bus_ops->suspend(host);
- if (err == -ENOSYS || !host->bus_ops->resume) {
- /*
- * We simply "remove" the card in this case.
- * It will be redetected on resume.
- */
- if (host->bus_ops->remove)
- host->bus_ops->remove(host);
- mmc_claim_host(host);
- mmc_detach_bus(host);
- mmc_release_host(host);
- host->pm_flags = 0;
- err = 0;
- }
}
mmc_bus_put(host);
@@ -1310,12 +1295,6 @@ int mmc_resume_host(struct mmc_host *host)
printk(KERN_WARNING "%s: error %d during resume "
"(card was removed?)\n",
mmc_hostname(host), err);
- if (host->bus_ops->remove)
- host->bus_ops->remove(host);
- mmc_claim_host(host);
- mmc_detach_bus(host);
- mmc_release_host(host);
- /* no need to bother upper layers */
err = 0;
}
}
@@ -1330,6 +1309,37 @@ int mmc_resume_host(struct mmc_host *host)
return err;
}
+/* Do the card removal on suspend if card is assumed removeable
+ * Do that in pm notifier while userspace isn't yet frozen, so we will be able
+ to sync the card.
+*/
+int mmc_pm_notify(struct notifier_block *notify_block,
+ unsigned long mode, void *unused)
+{
+ struct mmc_host *host = container_of(
+ notify_block, struct mmc_host, pm_notify);
+
+
+ switch (mode) {
+ case PM_HIBERNATION_PREPARE:
+ case PM_SUSPEND_PREPARE:
+
+ if (!host->bus_ops || host->bus_ops->suspend)
+ break;
+
+ if (host->bus_ops->remove)
+ host->bus_ops->remove(host);
+ mmc_claim_host(host);
+ mmc_detach_bus(host);
+ mmc_release_host(host);
+ host->pm_flags = 0;
+ break;
+
+ }
+
+ return 0;
+}
+
EXPORT_SYMBOL(mmc_resume_host);
#endif
@@ -1338,7 +1348,7 @@ static int __init mmc_init(void)
{
int ret;
- workqueue = create_singlethread_workqueue("kmmcd");
+ workqueue = create_freezeable_workqueue("kmmcd");
if (!workqueue)
return -ENOMEM;
diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
index 4735390..53f3406 100644
--- a/drivers/mmc/core/host.c
+++ b/drivers/mmc/core/host.c
@@ -17,6 +17,7 @@
#include <linux/pagemap.h>
#include <linux/leds.h>
#include <linux/slab.h>
+#include <linux/suspend.h>
#include <linux/mmc/host.h>
@@ -85,6 +86,8 @@ struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
init_waitqueue_head(&host->wq);
INIT_DELAYED_WORK(&host->detect, mmc_rescan);
INIT_DELAYED_WORK_DEFERRABLE(&host->disable, mmc_host_deeper_disable);
+ host->pm_notify.notifier_call = mmc_pm_notify;
+
/*
* By default, hosts do not support SGIO or large requests.
@@ -132,6 +135,7 @@ int mmc_add_host(struct mmc_host *host)
mmc_add_host_debugfs(host);
#endif
+ register_pm_notifier(&host->pm_notify);
mmc_start_host(host);
return 0;
@@ -158,6 +162,8 @@ void mmc_remove_host(struct mmc_host *host)
device_del(&host->class_dev);
led_trigger_unregister_simple(host->led);
+
+ unregister_pm_notifier(&host->pm_notify);
}
EXPORT_SYMBOL(mmc_remove_host);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index f65913c..b45812d 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -124,6 +124,7 @@ struct mmc_host {
unsigned int f_min;
unsigned int f_max;
u32 ocr_avail;
+ struct notifier_block pm_notify;
#define MMC_VDD_165_195 0x00000080 /* VDD voltage 1.65 - 1.95 */
#define MMC_VDD_20_21 0x00000100 /* VDD voltage 2.0 ~ 2.1 */
@@ -257,6 +258,8 @@ int mmc_card_can_sleep(struct mmc_host *host);
int mmc_host_enable(struct mmc_host *host);
int mmc_host_disable(struct mmc_host *host);
int mmc_host_lazy_disable(struct mmc_host *host);
+int mmc_pm_notify(struct notifier_block *notify_block, unsigned long, void *);
+
static inline void mmc_set_disable_delay(struct mmc_host *host,
unsigned int disable_delay)
--
1.7.0.4
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