On Fri, Apr 15, 2011 at 1:08 PM, Guennadi Liakhovetski
<g.liakhovet...@gmx.de> wrote:
> Currently there is a race in the MMC core between a card-detect
> rescan work and the clock-gating work, scheduled from a command
> completion. Fix it by removing the dedicated clock-gating mutex and
> using the MMC standard locking mechanism instead.
>
> Signed-off-by: Guennadi Liakhovetski <g.liakhovet...@gmx.de>
> Cc: Simon Horman <ho...@verge.net.au>
> Cc: Magnus Damm <d...@opensource.se>
> Cc: Linus Walleij <linus.wall...@linaro.org>
> ---
> drivers/mmc/core/host.c | 9 ++++-----
> include/linux/mmc/host.h | 1 -
> 2 files changed, 4 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index 461e6a1..2b200c1 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -94,7 +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);
> + mmc_claim_host(host);
> spin_lock_irqsave(&host->clk_lock, flags);
> if (!host->clk_requests) {
> spin_unlock_irqrestore(&host->clk_lock, flags);
> @@ -104,7 +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);
> + mmc_release_host(host);
> }
>
> /*
> @@ -130,7 +130,7 @@ void mmc_host_clk_ungate(struct mmc_host *host)
> {
> unsigned long flags;
>
> - mutex_lock(&host->clk_gate_mutex);
> + mmc_claim_host(host);
> spin_lock_irqsave(&host->clk_lock, flags);
> if (host->clk_gated) {
> spin_unlock_irqrestore(&host->clk_lock, flags);
> @@ -140,7 +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);
> + mmc_release_host(host);
> }
>
> /**
> @@ -215,7 +215,6 @@ 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 bcb793e..eb792cb 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -183,7 +183,6 @@ 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 */
> --
> 1.7.2.5
I've looked at this when Guennadi sent the original email and it looks
good to me FWIW.
A
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