Re: [regression, bisected] rockchip rk3399 video output breakage

[JeffyChen]

Hi Jakob,

Thanks for your message.

On 04/24/2018 08:19 PM, Jakob Unterwurzacher wrote:
> Full dmesg:
> https://gist.github.com/jakob-tsd/33cf395e355bf9bb6956c36438d999e7
>
> I have bisected the "master bind failed" down to:
>
> > commit 9176a303d971dc0fb35469c531c0d263667d2277
> > Author: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> > Date:   Fri Mar 23 15:38:10 2018 +0800
> >
> >     iommu/rockchip: Use IOMMU device for dma mapping operations
> >
> >     Use the first registered IOMMU device for dma mapping operations, and
> >     drop the domain platform device.
> >
> >     This is similar to exynos iommu driver.
> >
> >     Signed-off-by: Jeffy Chen <jeffy.chen@xxxxxxxxxxxxxx>
> >     Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
> >     Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
> >     Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
>
> Moving to one commit earlier brings the screen to life. Just with
> colorful garbage, but I guess that's a different problem.
>
> Is this a known issue with the IOMMU change?

right, i think it's a known issue, as the iommu failed to get clks:
[    1.525153] rk_iommu ff8f3f00.iommu: Failed to get clk 'iface': -2
[    1.525316] rk_iommu: probe of ff8f3f00.iommu failed with error -2
[    1.525484] rk_iommu ff903f00.iommu: Failed to get clk 'iface': -2
[    1.525643] rk_iommu: probe of ff903f00.iommu failed with error -2


there's a followed patch to add those clks to the dtsi, and also a fix 
patch to make those clks optional(by heiko):

https://www.spinics.net/lists/arm-kernel/msg645696.html

http://lists.infradead.org/pipermail/linux-rockchip/2018-April/020349.html

> Thanks,
> Jakob