mmc: msm_sdcc: Fix issue where clocks could be disabled mid transaction
msmsdcc_enable_clocks() was incorrectly being called depending on
the state of host->clks_on. This means the busclk idle timer was never
being deleted if the clock was already on.. Bogus.
Also fixes a possible double clk disable if the call to
del_timer_sync() in msmsdcc_disable_clocks() raced with
the busclk timer.
Signed-off-by: San Mehat <san@google.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
diff --git a/drivers/mmc/host/msm_sdcc.c b/drivers/mmc/host/msm_sdcc.c
index 8329fd6..47b1f25 100644
--- a/drivers/mmc/host/msm_sdcc.c
+++ b/drivers/mmc/host/msm_sdcc.c
@@ -61,7 +61,7 @@
#define CMD_SPINMAX 20
-static inline void
+static inline void
msmsdcc_disable_clocks(struct msmsdcc_host *host, int deferr)
{
WARN_ON(!host->clks_on);
@@ -72,9 +72,14 @@
mod_timer(&host->busclk_timer, jiffies + BUSCLK_TIMEOUT);
} else {
del_timer_sync(&host->busclk_timer);
- clk_disable(host->clk);
- clk_disable(host->pclk);
- host->clks_on = 0;
+ /* Need to check clks_on again in case the busclk
+ * timer fired
+ */
+ if (host->clks_on) {
+ clk_disable(host->clk);
+ clk_disable(host->pclk);
+ host->clks_on = 0;
+ }
}
}
@@ -83,21 +88,21 @@
{
int rc;
- WARN_ON(host->clks_on);
-
del_timer_sync(&host->busclk_timer);
- rc = clk_enable(host->pclk);
- if (rc)
- return rc;
- rc = clk_enable(host->clk);
- if (rc) {
- clk_disable(host->pclk);
- return rc;
+ if (!host->clks_on) {
+ rc = clk_enable(host->pclk);
+ if (rc)
+ return rc;
+ rc = clk_enable(host->clk);
+ if (rc) {
+ clk_disable(host->pclk);
+ return rc;
+ }
+ udelay(1 + ((3 * USEC_PER_SEC) /
+ (host->clk_rate ? host->clk_rate : msmsdcc_fmin)));
+ host->clks_on = 1;
}
- udelay(1 + ((3 * USEC_PER_SEC) /
- (host->clk_rate ? host->clk_rate : msmsdcc_fmin)));
- host->clks_on = 1;
return 0;
}
@@ -180,7 +185,8 @@
struct msmsdcc_host *host = (struct msmsdcc_host *)cmd->data;
msmsdcc_writel(host, host->cmd_timeout, MMCIDATATIMER);
- msmsdcc_writel(host, (unsigned int)host->curr.xfer_size, MMCIDATALENGTH);
+ msmsdcc_writel(host, (unsigned int)host->curr.xfer_size,
+ MMCIDATALENGTH);
msmsdcc_writel(host, host->cmd_pio_irqmask, MMCIMASK1);
msmsdcc_writel(host, host->cmd_datactrl, MMCIDATACTRL);
@@ -854,13 +860,7 @@
return;
}
- /* Need to drop the host lock here in case
- * the busclk wd fires
- */
- spin_unlock_irqrestore(&host->lock, flags);
- if (!host->clks_on)
- msmsdcc_enable_clocks(host);
- spin_lock_irqsave(&host->lock, flags);
+ msmsdcc_enable_clocks(host);
host->curr.mrq = mrq;
@@ -893,11 +893,10 @@
int rc;
unsigned long flags;
- if (!host->clks_on)
- msmsdcc_enable_clocks(host);
-
spin_lock_irqsave(&host->lock, flags);
+ msmsdcc_enable_clocks(host);
+
if (ios->clock) {
if (ios->clock != host->clk_rate) {
rc = clk_set_rate(host->clk, ios->clock);
@@ -1026,13 +1025,9 @@
msmsdcc_busclk_expired(unsigned long _data)
{
struct msmsdcc_host *host = (struct msmsdcc_host *) _data;
- unsigned long flags;
- spin_lock_irqsave(&host->lock, flags);
- dev_info(mmc_dev(host->mmc), "Bus clock timer expired\n");
if (host->clks_on)
msmsdcc_disable_clocks(host, 0);
- spin_unlock_irqrestore(&host->lock, flags);
}
static int
@@ -1324,10 +1319,8 @@
if (mmc->card && mmc->card->type != MMC_TYPE_SDIO)
rc = mmc_suspend_host(mmc, state);
- if (!rc) {
+ if (!rc)
msmsdcc_writel(host, 0, MMCIMASK0);
-
- }
if (host->clks_on)
msmsdcc_disable_clocks(host, 0);
}