This adds a mutex to protect from races between gate and ungate calls colliding.
Cc: Ohad Ben-Cohen <[email protected]> Signed-off-by: Linus Walleij <[email protected]> --- This should fix the race observed by Ohad earlier. --- drivers/mmc/core/host.c | 11 ++++++++--- include/linux/mmc/host.h | 1 + 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c index f74b386..92e3370 100644 --- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -68,9 +68,9 @@ static void mmc_host_clk_gate_delayed(struct mmc_host *host) unsigned long flags; if (!freq) { - pr_err("%s: frequency set to 0 in disable function, " - "this means the clock is already disabled.\n", - mmc_hostname(host)); + pr_debug("%s: frequency set to 0 in disable function, " + "this means the clock is already disabled.\n", + mmc_hostname(host)); return; } /* @@ -94,6 +94,7 @@ static void mmc_host_clk_gate_delayed(struct mmc_host *host) spin_unlock_irqrestore(&host->clk_lock, flags); return; } + mutex_lock(&host->clk_gate_mutex); spin_lock_irqsave(&host->clk_lock, flags); if (!host->clk_requests) { spin_unlock_irqrestore(&host->clk_lock, flags); @@ -103,6 +104,7 @@ static void mmc_host_clk_gate_delayed(struct mmc_host *host) pr_debug("%s: gated MCI clock\n", mmc_hostname(host)); } spin_unlock_irqrestore(&host->clk_lock, flags); + mutex_unlock(&host->clk_gate_mutex); } /* @@ -128,6 +130,7 @@ void mmc_host_clk_ungate(struct mmc_host *host) { unsigned long flags; + mutex_lock(&host->clk_gate_mutex); spin_lock_irqsave(&host->clk_lock, flags); if (host->clk_gated) { spin_unlock_irqrestore(&host->clk_lock, flags); @@ -137,6 +140,7 @@ void mmc_host_clk_ungate(struct mmc_host *host) } host->clk_requests++; spin_unlock_irqrestore(&host->clk_lock, flags); + mutex_unlock(&host->clk_gate_mutex); } /** @@ -214,6 +218,7 @@ static inline void mmc_host_clk_init(struct mmc_host *host) host->clk_gated = false; INIT_WORK(&host->clk_gate_work, mmc_host_clk_gate_work); spin_lock_init(&host->clk_lock); + mutex_init(&host->clk_gate_mutex); } /** diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 955bc10..53496bb 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -178,6 +178,7 @@ struct mmc_host { struct work_struct clk_gate_work; /* delayed clock gate */ unsigned int clk_old; /* old clock value cache */ spinlock_t clk_lock; /* lock for clk fields */ + struct mutex clk_gate_mutex; /* mutex for clock gating */ #endif /* host specific block data */ -- 1.6.3.3 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
