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

From: Stephen Warren
Date: Thu Jun 13 2013 - 11:15:10 EST


On 06/13/2013 03:53 AM, Mayuresh Kulkarni wrote:

Patch description?


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

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

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:

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

> @@ -328,10 +338,51 @@ static int __exit gr2d_remove(struct platform_device *pdev)
>
> host1x_channel_free(gr2d->channel);
> clk_disable_unprepare(gr2d->clk);

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

> +#ifdef CONFIG_PM_RUNTIME
> + pm_runtime_disable(&pdev->dev);
> +#endif

Similarly, perhaps something like the following here:

pm_runtime_disable(&pdev->dev);
if (!pm_runtime_status_suspended(&pdev->dev))
tegra20_i2s_runtime_suspend(&pdev->dev);

> @ -591,10 +592,18 @@ int host1x_job_submit(struct host1x_job *job)
> {
> struct host1x *host = dev_get_drvdata(job->channel->dev->parent);
>
> +#ifdef CONFIG_PM_RUNTIME
> + pm_runtime_get_sync(job->channel->dev);
> +#endif
> +
> return host1x_hw_channel_submit(host, job);
> }
>
> int host1x_job_complete(struct host1x_job *job)
> {
> +#ifdef CONFIG_PM_RUNTIME
> + return pm_runtime_put(job->channel->dev);
> +#else
> return 0;
> +#endif
> }

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
if !PM_RUNTIME.
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