Re: [PATCH v9 2/3] media: rockchip: Add a driver for Rockchip's camera interface

[Mehdi Djait <mehdi.djait@bootlin.com>]

Hello Michael,

On Wed, Nov 08, 2023 at 09:50:25AM +0100, Michael Riesch wrote:
> Hi Mehdi,
> I applied your patches and added some modifications (= crude hacks) on
> top of them to bring up the RK3568 VICAP (note that I don't have any
> PX30 hardware). This setup is not yet able to capture the input stream
> (from a HDMI receiver chip), but I am on it.
> 
> One question popped up: to get the cif driver to probe with my device
> tree I had to request the IRQ with IRQF_SHARED. This is due to the
> approach that the CIF block has one IRQ but is represented by two
> drivers: the cif driver and the rockchip-iommu driver.

It was IRQF_SHARED when I submitted the v6 but changed it after reviews.

> 
> Subsequently I was surprised that you are not using the MMU at all,
> although the PX30 VIP features one. Is there any particular reason for that?

No particular reason. The IOMMU did not work and was not included when the 
patch series for this driver were submitted years ago. I focused on
fixing all the issues I found, complying with v4l2 guidelines and
getting an upstreamable driver: so I did not add the support.

> 
> Can we request the IRQ with IRQF_SHARED anyway?

Yes I will change it back to SHARED.

--
Kind Regards
Mehdi Djait