Re: [PATCH] mmc: fix to refer NULL pointer

From: Guennadi Liakhovetski
Date: Sun Jan 27 2013 - 03:10:29 EST


On Sat, 26 Jan 2013, Joonyoung Shim wrote:

> Check whether host->sdio_irq_thread is NULL before wake_up_process() is
> called about host->sdio_irq_thread.

Actually, mmc_signal_sdio_irq() shouldn't be called if SDIO IRQ isn't
used...

Thanks
Guennadi

>
> Signed-off-by: Joonyoung Shim <jy0922.shim@xxxxxxxxxxx>
> ---
> Currently the kernel panic to refer NULL pointer about
> host->sdio_irq_thread are occuring at the trats board using Samsung
> SDHCI driver.
>
> include/linux/mmc/host.h | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 61a10c1..2950fea 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -372,7 +372,8 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
> {
> host->ops->enable_sdio_irq(host, 0);
> host->sdio_irq_pending = true;
> - wake_up_process(host->sdio_irq_thread);
> + if (host->sdio_irq_thread)
> + wake_up_process(host->sdio_irq_thread);
> }
>
> #ifdef CONFIG_REGULATOR
> --
> 1.7.9.5
>
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---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/
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