Re: [PATCHv3 2/4] drm/tegra: Add runtime pm support for gr2d

From: Arto Merilainen
Date: Wed Oct 02 2013 - 01:44:25 EST


On 10/01/2013 09:14 PM, Stephen Warren wrote:
On 09/24/2013 06:05 AM, Arto Merilainen wrote:
diff --git a/drivers/gpu/host1x/drm/gr2d.c b/drivers/gpu/host1x/drm/gr2d.c

@@ -327,11 +336,48 @@ static int __exit gr2d_remove(struct platform_device *pdev)
host1x_syncpt_free(gr2d->client.syncpts[i]);

host1x_channel_free(gr2d->channel);
+
+ if (pm_runtime_enabled(&pdev->dev))
+ pm_runtime_disable(&pdev->dev);
+ else
+ gr2d_runtime_suspend(&pdev->dev);

This code is slightly different to the code in e.g.
sound/soc/tegra/tegra20_i2s.c:remove(), whereas the code in probe() is
identical. I'm not sure whether there's some advantage in this version?
If so, perhaps the sound drivers should be updated to be consistent. If
not, perhaps this driver should do the same thing as the I2S driver, so
we keep the drivers consistent, and provide the same "example" code
everywhere.

Hmm. I cannot immediately see any advantage in this version... I will update the patch.


+static int gr2d_runtime_suspend(struct device *dev)
+{
+ struct gr2d *gr2d;
+
+ gr2d = dev_get_drvdata(dev);
+ if (!gr2d)
+ return -EINVAL;

Presumably, gr2d will never be NULL here, unless there's some chronic
bug. Can't we re-write those last 5 lines as simply:

struct gr2d *grd2 = dev_get_drvdata(dev);

If that's not valid, we should probably update the audio drivers (and
perhaps others) too.

I think you are correct. I cannot see any reason why that check is required.

- Arto
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