Re: [PATCH v2 2/4] gpu: host1x: add runtime pm support for gr2d

From: Mayuresh Kulkarni
Date: Fri Jun 14 2013 - 10:45:56 EST

On Thursday 13 June 2013 08:44 PM, Stephen Warren wrote:
On 06/13/2013 03:53 AM, Mayuresh Kulkarni wrote:

Patch description?

I thought the patch subject is sufficient to tell what it is it doing. Description here would be repetition in my opinion.

Also, the cover letter for the patch-set series is verbose enough.

diff --git a/drivers/gpu/host1x/drm/gr2d.c b/drivers/gpu/host1x/drm/gr2d.c

+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_get_sync(&pdev->dev);
err = clk_prepare_enable(gr2d->clk);
if (err) {
dev_err(dev, "cannot turn on clock\n");
return err;

The #else block here is a cut/paste of the body of
gr2d_runtime_resume(). It'd be better to call that function instead. The
following is what I ended up with in the Tegra ASoC driver in order to
support runtime PM on or off:

if (!pm_runtime_enabled(&pdev->dev)) {
ret = tegra20_i2s_runtime_resume(&pdev->dev);
if (ret)
goto err_pm_disable;

Thanks for the tip. Runtime detection is better than compile time here.

@@ -328,10 +338,51 @@ static int __exit gr2d_remove(struct platform_device *pdev)


Don't you need to remove that clk disable, or make it conditional upon

Yes you are correct.

+ pm_runtime_disable(&pdev->dev);

Similarly, perhaps something like the following here:

if (!pm_runtime_status_suspended(&pdev->dev))

@ -591,10 +592,18 @@ int host1x_job_submit(struct host1x_job *job)
struct host1x *host = dev_get_drvdata(job->channel->dev->parent);

+ pm_runtime_get_sync(job->channel->dev);
return host1x_hw_channel_submit(host, job);

int host1x_job_complete(struct host1x_job *job)
+ return pm_runtime_put(job->channel->dev);
return 0;

I don't think you need any of those ifdefs; simply call the
pm_runtime_*() functions all the time, and they'll be successful no-ops

OK. But I thought it will be better to be verbose (which is not needed).

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at