Re: [PATCH] MMC: TMIO: add runtime PM calls to global suspend() /

[Simon Horman <horms@verge.net.au>]

Hi Guennadi,

On Thu, Apr 21, 2011 at 12:32:54PM +0200, Guennadi Liakhovetski wrote:
> The TMIO MMC driver cannot generally suspend itself at runtime even
> with no card inserted, because otherwise it wouldn't be able to detect
> new cards. But when the system goes down for a global suspend, we can
> use runtime PM calls to let it activate platform-specific PM hooks,
> e.g., to switch off respective power domains.
> 
> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
> ---
>  drivers/mmc/host/tmio_mmc.h     |    2 ++
>  drivers/mmc/host/tmio_mmc_pio.c |    6 ++++++
>  2 files changed, 8 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index 249c724..58138a2 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -52,6 +52,8 @@ struct tmio_mmc_host {
>  	void (*set_pwr)(struct platform_device *host, int state);
>  	void (*set_clk_div)(struct platform_device *host, int state);
>  
> +	int			pm_error;

I wonder if instead of adding an whole int to effectively
store one bit we could use some of the spare space in the
sdio_irq_enabled element, which is also an int that effectively
stores one bit.

Perhaps a bitmask or a bitfield?

I was thinking of doing something similar when adding support
for multiple IRQ vectors, as my current code also needs, wait for it,
one bit :-)

> +
>  	/* pio related stuff */
>  	struct scatterlist      *sg_ptr;
>  	struct scatterlist      *sg_orig;
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
> index d1791ba..26598f1 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -980,6 +980,8 @@ int tmio_mmc_host_suspend(struct device *dev)
>  	if (!ret)
>  		tmio_mmc_disable_mmc_irqs(host, TMIO_MASK_ALL);
>  
> +	host->pm_error = pm_runtime_put_sync(dev);
> +
>  	return ret;
>  }
>  EXPORT_SYMBOL(tmio_mmc_host_suspend);
> @@ -987,6 +989,10 @@ EXPORT_SYMBOL(tmio_mmc_host_suspend);
>  int tmio_mmc_host_resume(struct device *dev)
>  {
>  	struct mmc_host *mmc = dev_get_drvdata(dev);
> +	struct tmio_mmc_host *host = mmc_priv(mmc);
> +
> +	if (!host->pm_error)
> +		pm_runtime_get_sync(dev);
>  
>  	tmio_mmc_reset(mmc_priv(mmc));
>  
> -- 
> 1.7.2.5
>