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 7289e99..5ae6b15 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1192,7 +1192,7 @@
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 @@
}
/*
- * 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 @@
spin_unlock_irqrestore(&host->lock, flags);
- mmc_power_off(host);
-
mmc_bus_put(host);
}
@@ -1893,6 +1890,7 @@
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 @@
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 @@
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 d9411ed..14664f1 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -43,6 +43,7 @@
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 f73fceea..3b7c069 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -892,6 +892,7 @@
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 0370e03..4c281a4 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -1043,6 +1043,7 @@
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 262fff0..ac492ac 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -597,6 +597,7 @@
mmc_claim_host(host);
mmc_detach_bus(host);
+ mmc_power_off(host);
mmc_release_host(host);
}
}