Re: rk3399: Graphical artifacts when running for-next

Robert Foss
2019-02-21T15:46:19Z

On 2/21/19 2:26 PM, Heiko Stuebner wrote:
> Hi Robert,
>
> Am Donnerstag, 21. Februar 2019, 11:27:15 CET schrieb Robert Foss:
>> Hey Heiko,
>>
>> I've just started booting the RK3399 based Radxa Rock Pi 4 on the mainline
>> kernel. Specifically on linux-rockchip/for-next, with an additional patch
>> adding the GPU DT node[1].
>>
>> Unfortunately I'm seeing an artifact on all display output[2].
>> It, from the VT to 3D content.
>>
>> Is this an issue that has been encountered before?
>
> I haven't seen something like this before. I do test graphics
> on most Rockchip socs regularly (right now dw-hdmi only
> on non-rk3399 socs though).
>
> Did you try full linux-next as well? My for-next branch obviously
> only carries dt/soc-driver stuff but not things like drm-misc.
>
> One possible issue might be the generated clocks. You could check
> $debug/clk/clk_summary for the dclk_vopX to see if that matches
> the suggested clock for the mode. (For example check the requested
> rate in rockchip_vop.c against what it actually gets).
>

I had a look using the current linux-next/master, and I'm seeing the same results.
Commit: 550f4769c7c4 - Add linux-next specific files for 20190221

I had also look at the debugfs output:
# cat /sys/kernel/debug/clk/clk_summary | grep dclk_vop
dclk_vop0_div 0 1 0 27000000 0 0 50000
dclk_vop0 0 2 0 27000000 0 0 50000
dclk_vop0_frac 0 0 0 1350000 0 0 50000
dclk_vop1_div 1 1 0 59400000 0 0 50000
dclk_vop1 2 2 0 59400000 0 0 50000
dclk_vop1_frac 0 0 0 2970000 0 0 50000

But I can't find a file named rockchip_vop.c exactly. And I'm not entirely sure
about how to decipher the expected values from the driver.

> Heiko
>
>
>> [1] https://patchwork.kernel.org/patch/10817637/mbox/
>> [2] https://photos.app.goo.gl/ArffJ3785JSeQatW7
>>
>>
>> Rob.
>>
>
>
>
>