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/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)