mmc: core: Ensure clocks are always enabled before host interaction
Ensure clocks are always enabled before any interaction with the
host controller driver. This makes sure that there is no race
between host execution and the core layer turning off clocks
in different context with clock gating framework.
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Per Forlin <per.forlin@stericsson.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index f545a3e..b3063b7 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -290,8 +290,11 @@
static void mmc_pre_req(struct mmc_host *host, struct mmc_request *mrq,
bool is_first_req)
{
- if (host->ops->pre_req)
+ if (host->ops->pre_req) {
+ mmc_host_clk_hold(host);
host->ops->pre_req(host, mrq, is_first_req);
+ mmc_host_clk_release(host);
+ }
}
/**
@@ -306,8 +309,11 @@
static void mmc_post_req(struct mmc_host *host, struct mmc_request *mrq,
int err)
{
- if (host->ops->post_req)
+ if (host->ops->post_req) {
+ mmc_host_clk_hold(host);
host->ops->post_req(host, mrq, err);
+ mmc_host_clk_release(host);
+ }
}
/**
@@ -620,7 +626,9 @@
int err;
host->en_dis_recurs = 1;
+ mmc_host_clk_hold(host);
err = host->ops->enable(host);
+ mmc_host_clk_release(host);
host->en_dis_recurs = 0;
if (err) {
@@ -640,7 +648,9 @@
int err;
host->en_dis_recurs = 1;
+ mmc_host_clk_hold(host);
err = host->ops->disable(host, lazy);
+ mmc_host_clk_release(host);
host->en_dis_recurs = 0;
if (err < 0) {
@@ -1203,8 +1213,11 @@
host->ios.signal_voltage = signal_voltage;
- if (host->ops->start_signal_voltage_switch)
+ if (host->ops->start_signal_voltage_switch) {
+ mmc_host_clk_hold(host);
err = host->ops->start_signal_voltage_switch(host, &host->ios);
+ mmc_host_clk_release(host);
+ }
return err;
}
diff --git a/drivers/mmc/core/host.h b/drivers/mmc/core/host.h
index fb8a5cd..08a7852 100644
--- a/drivers/mmc/core/host.h
+++ b/drivers/mmc/core/host.h
@@ -14,27 +14,6 @@
int mmc_register_host_class(void);
void mmc_unregister_host_class(void);
-
-#ifdef CONFIG_MMC_CLKGATE
-void mmc_host_clk_hold(struct mmc_host *host);
-void mmc_host_clk_release(struct mmc_host *host);
-unsigned int mmc_host_clk_rate(struct mmc_host *host);
-
-#else
-static inline void mmc_host_clk_hold(struct mmc_host *host)
-{
-}
-
-static inline void mmc_host_clk_release(struct mmc_host *host)
-{
-}
-
-static inline unsigned int mmc_host_clk_rate(struct mmc_host *host)
-{
- return host->ios.clock;
-}
-#endif
-
void mmc_host_deeper_disable(struct work_struct *work);
#endif
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index c63ad03..5017f93 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -451,9 +451,11 @@
* information and let the hardware specific code
* return what is possible given the options
*/
+ mmc_host_clk_hold(card->host);
drive_strength = card->host->ops->select_drive_strength(
card->sw_caps.uhs_max_dtr,
host_drv_type, card_drv_type);
+ mmc_host_clk_release(card->host);
err = mmc_sd_switch(card, 1, 2, drive_strength, status);
if (err)
@@ -660,9 +662,12 @@
goto out;
/* SPI mode doesn't define CMD19 */
- if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning)
+ if (!mmc_host_is_spi(card->host) && card->host->ops->execute_tuning) {
+ mmc_host_clk_hold(card->host);
err = card->host->ops->execute_tuning(card->host,
MMC_SEND_TUNING_BLOCK);
+ mmc_host_clk_release(card->host);
+ }
out:
kfree(status);
@@ -850,8 +855,11 @@
if (!reinit) {
int ro = -1;
- if (host->ops->get_ro)
+ if (host->ops->get_ro) {
+ mmc_host_clk_hold(card->host);
ro = host->ops->get_ro(host);
+ mmc_host_clk_release(card->host);
+ }
if (ro < 0) {
pr_warning("%s: host does not "
@@ -967,8 +975,11 @@
* Since initialization is now complete, enable preset
* value registers for UHS-I cards.
*/
- if (host->ops->enable_preset_value)
+ if (host->ops->enable_preset_value) {
+ mmc_host_clk_hold(card->host);
host->ops->enable_preset_value(host, true);
+ mmc_host_clk_release(card->host);
+ }
} else {
/*
* Attempt to change to high-speed (if supported)
@@ -1151,8 +1162,11 @@
return err;
/* Disable preset value enable if already set since last time */
- if (host->ops->enable_preset_value)
+ if (host->ops->enable_preset_value) {
+ mmc_host_clk_hold(host);
host->ops->enable_preset_value(host, false);
+ mmc_host_clk_release(host);
+ }
err = mmc_send_app_op_cond(host, 0, &ocr);
if (err)
diff --git a/drivers/mmc/core/sdio_irq.c b/drivers/mmc/core/sdio_irq.c
index 68f81b9..f573e7f 100644
--- a/drivers/mmc/core/sdio_irq.c
+++ b/drivers/mmc/core/sdio_irq.c
@@ -146,15 +146,21 @@
}
set_current_state(TASK_INTERRUPTIBLE);
- if (host->caps & MMC_CAP_SDIO_IRQ)
+ if (host->caps & MMC_CAP_SDIO_IRQ) {
+ mmc_host_clk_hold(host);
host->ops->enable_sdio_irq(host, 1);
+ mmc_host_clk_release(host);
+ }
if (!kthread_should_stop())
schedule_timeout(period);
set_current_state(TASK_RUNNING);
} while (!kthread_should_stop());
- if (host->caps & MMC_CAP_SDIO_IRQ)
+ if (host->caps & MMC_CAP_SDIO_IRQ) {
+ mmc_host_clk_hold(host);
host->ops->enable_sdio_irq(host, 0);
+ mmc_host_clk_release(host);
+ }
pr_debug("%s: IRQ thread exiting with code %d\n",
mmc_hostname(host), ret);
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 0beba1e..73e5ee8 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -444,4 +444,23 @@
return !(host->caps2 & MMC_CAP2_BOOTPART_NOACC);
}
+#ifdef CONFIG_MMC_CLKGATE
+void mmc_host_clk_hold(struct mmc_host *host);
+void mmc_host_clk_release(struct mmc_host *host);
+unsigned int mmc_host_clk_rate(struct mmc_host *host);
+
+#else
+static inline void mmc_host_clk_hold(struct mmc_host *host)
+{
+}
+
+static inline void mmc_host_clk_release(struct mmc_host *host)
+{
+}
+
+static inline unsigned int mmc_host_clk_rate(struct mmc_host *host)
+{
+ return host->ios.clock;
+}
+#endif
#endif /* LINUX_MMC_HOST_H */