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;
}