Re: [PATCH] drm/i915: get/put runtime PM at i915_semaphore_status

[Ben Widawsky <ben@bwidawsk.net>]

On Wed, Jul 09, 2014 at 02:31:57PM -0300, Paulo Zanoni wrote:
> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
> 
> Otherwise we will print some WARNs when we read registers and the
> machine is suspended.

Do all register reads really require this? If so, shouldn't it work
similarly to forcewake? I didn't follow any of the PM mails, so feel
free to ignore if this has been discussed and addressed already.

> 
> Testcase: igt/pm_rpm/debugfs-read
> Cc: Ben Widawsky <ben@bwidawsk.net>
> Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>

Reviewed-by: Ben Widawsky <ben@bwidawsk.net>

> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> I still dream with the day we will have a system that will run IGT on our
> patches/series _before_ they are applied to the tree, and tell us in case some
> testcase fails or gives us a WARN.
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 0c665df..1ff56ec 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2316,6 +2316,7 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
>  	ret = mutex_lock_interruptible(&dev->struct_mutex);
>  	if (ret)
>  		return ret;
> +	intel_runtime_pm_get(dev_priv);
>  
>  	if (IS_BROADWELL(dev)) {
>  		struct page *page;
> @@ -2365,6 +2366,7 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
>  	}
>  	seq_putc(m, '\n');
>  
> +	intel_runtime_pm_put(dev_priv);
>  	mutex_unlock(&dev->struct_mutex);
>  	return 0;
>  }
> -- 
> 2.0.0
> 

-- 
Ben Widawsky, Intel Open Source Technology Center