Re: [PATCH 2/3] tmio_mmc / PM: Use PM QoS latency constraint

[Adrian Hunter <adrian.hunter@intel.com>]

On 08/03/12 01:29, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rjw@sisk.pl>
> 
> Make tmio_mmc call dev_pm_qos_expose_latency_limit() to expose
> the PM QoS latency limit to user space and specify the initial
> value of it as 100 microseconds.
> 
> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
> ---
>  drivers/mmc/host/tmio_mmc_pio.c |    5 +++++
>  1 file changed, 5 insertions(+)
> 
> Index: linux/drivers/mmc/host/tmio_mmc_pio.c
> ===================================================================
> --- linux.orig/drivers/mmc/host/tmio_mmc_pio.c
> +++ linux/drivers/mmc/host/tmio_mmc_pio.c
> @@ -39,6 +39,7 @@
>  #include <linux/module.h>
>  #include <linux/pagemap.h>
>  #include <linux/platform_device.h>
> +#include <linux/pm_qos.h>
>  #include <linux/pm_runtime.h>
>  #include <linux/scatterlist.h>
>  #include <linux/spinlock.h>
> @@ -955,6 +956,8 @@ int __devinit tmio_mmc_host_probe(struct
>  
>  	mmc_add_host(mmc);
>  
> +	dev_pm_qos_expose_latency_limit(&pdev->dev, 100);
> +
>  	/* Unmask the IRQs we want to know about */
>  	if (!_host->chan_rx)
>  		irq_mask |= TMIO_MASK_READOP;
> @@ -993,6 +996,8 @@ void tmio_mmc_host_remove(struct tmio_mm
>  		|| host->mmc->caps & MMC_CAP_NONREMOVABLE)
>  		pm_runtime_get_sync(&pdev->dev);
>  
> +	dev_pm_qos_hide_latency_limit(&pdev->dev);

Is it really necessary to hide the latency limit before destroying the
device?  Presumably QoS code could (or does) take care of it.

> +
>  	mmc_remove_host(host->mmc);
>  	cancel_work_sync(&host->done);
>  	cancel_delayed_work_sync(&host->delayed_reset_work);
> 
>