mmc: core: Fix hangs related to insert/remove of cards

During a rescan operation mmc_attach(sd|mmc|sdio) functions are
called. The error handling in these function can trigger a detach
of the bus, which also meant a power off. This is not notified by
the rescan operation which then continues to the next attach function.

If a power off has been done, the framework must never send any
new commands to the host driver, without first doing a new power up.
This will most likely trigger any host driver to hang.

Moving power off out of detach and instead handle power off
separately when it is actually needed, solves the issue.

Signed-off-by: Ulf Hansson <ulf.hansson@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Cc: <stable@kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7289e999d1fce94cca7a05fbf02b947cdba41e13..5ae6b159dbea1af4c327402d33e86e7c95ff400d 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1192,7 +1192,7 @@ static void mmc_power_up(struct mmc_host *host)
        mmc_host_clk_release(host);
 }
 
-static void mmc_power_off(struct mmc_host *host)
+void mmc_power_off(struct mmc_host *host)
 {
        mmc_host_clk_hold(host);
 
@@ -1289,8 +1289,7 @@ void mmc_attach_bus(struct mmc_host *host, const struct mmc_bus_ops *ops)
 }
 
 /*
- * Remove the current bus handler from a host. Assumes that there are
- * no interesting cards left, so the bus is powered down.
+ * Remove the current bus handler from a host.
  */
 void mmc_detach_bus(struct mmc_host *host)
 {
@@ -1307,8 +1306,6 @@ void mmc_detach_bus(struct mmc_host *host)
 
        spin_unlock_irqrestore(&host->lock, flags);
 
-       mmc_power_off(host);
-
        mmc_bus_put(host);
 }
 
@@ -1893,6 +1890,7 @@ void mmc_stop_host(struct mmc_host *host)
 
                mmc_claim_host(host);
                mmc_detach_bus(host);
+               mmc_power_off(host);
                mmc_release_host(host);
                mmc_bus_put(host);
                return;
@@ -2022,6 +2020,7 @@ int mmc_suspend_host(struct mmc_host *host)
                                host->bus_ops->remove(host);
                        mmc_claim_host(host);
                        mmc_detach_bus(host);
+                       mmc_power_off(host);
                        mmc_release_host(host);
                        host->pm_flags = 0;
                        err = 0;
@@ -2109,6 +2108,7 @@ int mmc_pm_notify(struct notifier_block *notify_block,
                        host->bus_ops->remove(host);
 
                mmc_detach_bus(host);
+               mmc_power_off(host);
                mmc_release_host(host);
                host->pm_flags = 0;
                break;

diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index d9411ed2a39bf6490a5a788629d45a628e14e6fe..14664f1fb16fb560c526dd30817cc10ae6db1adf 100644 (file)
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -43,6 +43,7 @@ int mmc_set_signal_voltage(struct mmc_host *host, int signal_voltage,
                           bool cmd11);
 void mmc_set_timing(struct mmc_host *host, unsigned int timing);
 void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);
+void mmc_power_off(struct mmc_host *host);
 
 static inline void mmc_delay(unsigned int ms)
 {

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index f73fceea5dbd9611613162f36871101d5ec14ad5..3b7c069a4ea6e2e8be6edbacc8f15f0a1a76c26d 100644 (file)
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -892,6 +892,7 @@ static void mmc_detect(struct mmc_host *host)
 
                mmc_claim_host(host);
                mmc_detach_bus(host);
+               mmc_power_off(host);
                mmc_release_host(host);
        }
 }

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 0370e03e314253f027a36aa994591ea2817f0826..4c281a4bf0589d6f8393f16e38e341bc31ffd45d 100644 (file)
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1043,6 +1043,7 @@ static void mmc_sd_detect(struct mmc_host *host)
 
                mmc_claim_host(host);
                mmc_detach_bus(host);
+               mmc_power_off(host);
                mmc_release_host(host);
        }
 }

diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 262fff0191779301232fefba02bc8c916e026b33..ac492ac974e16458bec3dfce48cc858357b8dbea 100644 (file)
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -597,6 +597,7 @@ out:
 
                mmc_claim_host(host);
                mmc_detach_bus(host);
+               mmc_power_off(host);
                mmc_release_host(host);
        }
 }