Re: [PATCH v4 3/4] media: raspberrypi: Add support for RP1-CFE

From: Tomi Valkeinen
Date: Tue Sep 10 2024 - 05:56:58 EST


On 10/09/2024 12:19, Jacopo Mondi wrote:

However, I think this current patch is correct (assuming the above
reasoning on i2c sensor drivers is correct) and doesn't require
CONFIG_PM, so I would be tempted to keep this version.

I think the existence of this discussion alone proves my point that we should only support PM-case, unless !PM is a requirement =).

But if you do want to keep !PM:

Is there a reason why not mark the device as active with pm_runtime_set_active() after calling pispbe_runtime_resume and before accessing the device? That feels like the most logical way to use the function, and it would be right regardless whether the core will enable the parents before probe() or not.

And not related to the BE or CFE drivers, but it strikes me odd that to support PM and !PM we need to play with these tricks. I think the core should just do the right thing if the driver does pm_runtime_get_sync() even with !PM (although maybe the time has passed to be able to do that).

Tomi