Re: [PATCH 1/3] drm/tegra: Add NVJPG driver

[Diogo Ivo]

Hi Thierry,

On 6/10/25 9:44 AM, Thierry Reding wrote:
> On Tue, Jun 10, 2025 at 12:26:07PM +0900, Mikko Perttunen wrote:
> > On 6/6/25 7:45 PM, Diogo Ivo wrote:
> > > Add support for booting and using NVJPG on Tegra210 to the Host1x
> > > and TegraDRM drivers. This driver only supports the new TegraDRM uAPI.
> >
> > Hello Diogo -- I'm happy to see this driver!
>
> So am I, nice work!

Thank you Mikko and Thierry for the kind words :)

> [...]
> > > +	if (IS_ERR(nvjpg->regs))
> > > +		return PTR_ERR(nvjpg->regs);
> > > +
> > > +	nvjpg->rst = devm_reset_control_get_exclusive_released(&pdev->dev, "nvjpg");
> > > +	if (IS_ERR(nvjpg->rst)) {
> > > +		err = PTR_ERR(nvjpg->rst);
> > > +
> > > +		if (err != -EBUSY || WARN_ON(!pdev->dev.pm_domain)) {
> > > +			dev_err(&pdev->dev, "failed to get reset control: %d\n",
> > > +				err);
> > > +			return err;
> > > +		}
> > > +
> > > +		/*
> > > +		 * At this point, the reset control is most likely being used
> > > +		 * by the generic power domain implementation. With any luck
> > > +		 * the power domain will have taken care of resetting the SOR
> > > +		 * and we don't have to do anything.
> > > +		 */
> > > +		nvjpg->rst = NULL;
> > > +	}
> >
> > I see you've taken this from sor.c, but I think it should be unnecessary. I
> > imagine the code in sor.c is overcomplicated as well, maybe because we used
> > not to have the power domain implementation.
>
> Agreed. SOR is also slightly older than NVJPG and used on Tegra124 where
> we don't use power domains, so most of these quirks are for backwards-
> compatibility. If we can avoid them for NVJPG, that'd be great.

Sounds good, I'll get rid of this explicit handling in v2.

Thanks,
Diogo