[PATCH v2 0/2] drm/rockchip: dw_hdmi: Add 4k at 30 support

[Robin Murphy]

On 2022-10-05 12:10, Sascha Hauer wrote:
> On Wed, Oct 05, 2022 at 12:51:57PM +0200, Dan Johansen wrote:
>>
>> Den 05.10.2022 kl. 12.06 skrev Sascha Hauer:
>>> On Wed, Sep 28, 2022 at 10:39:27AM +0200, Dan Johansen wrote:
>>>> Den 28.09.2022 kl. 10.37 skrev Sascha Hauer:
>>>>> On Tue, Sep 27, 2022 at 07:53:54PM +0200, Dan Johansen wrote:
>>>>>> Den 26.09.2022 kl. 12.30 skrev Michael Riesch:
>>>>>>> Hi Sascha,
>>>>>>>
>>>>>>> On 9/26/22 10:04, Sascha Hauer wrote:
>>>>>>>> This series adds support for 4k at 30 to the rockchip HDMI controller. This
>>>>>>>> has been tested on a rk3568 rock3a board. It should be possible to add
>>>>>>>> 4k at 60 support the same way, but it doesn't work for me, so let's add
>>>>>>>> 4k at 30 as a first step.
>>>>>>>> 														     Sascha
>>>>>>>>
>>>>>>>> Changes since v1:
>>>>>>>> - Allow non standard clock rates only on Synopsys phy as suggested by
>>>>>>>>       Robin Murphy
>>>>>>>>
>>>>>>>> Sascha Hauer (2):
>>>>>>>>       drm/rockchip: dw_hdmi: relax mode_valid hook
>>>>>>>>       drm/rockchip: dw_hdmi: Add support for 4k at 30 resolution
>>>>>>>>
>>>>>>>>      drivers/gpu/drm/rockchip/dw_hdmi-rockchip.c | 34 ++++++++++++++++-----
>>>>>>>>      1 file changed, 27 insertions(+), 7 deletions(-)
>>>>>>> Thanks for the v2! On a RK3568 EVB1 with a HP 27f 4k monitor
>>>>>>>
>>>>>>> Tested-by: Michael Riesch <michael.riesch at wolfvision.net>
>>>>>> Sadly this still doesn't give my display out on my 2k monitor. Not even just
>>>>>> 1080p picture like the old current implementation does.
>>>>> By "like the old current implementation" you mean that this patchset
>>>>> introduces a regression for you?
>>>> Yes. What currently in the kernel at least shows as 1080p on my 2K monitor,
>>>> while this patchset turns off the screen.
>>> Which SoC are you testing this on? I assume RK3568, right? Which patch
>>> introduces that regression, the first or the second one?
>> I tested on the Odroid M, which is rk3568.
>> I have only applied them both, as I was under the impression that both are
>> needed for the 4k support.
> 
> Yes, both I needed, but I am interested which one introduces the
> regression as I can't reproduce it.

One thing that might be worthwhile is to compare what "drm.debug=4" 
output says about the chosen mode and its clock rate vs. what 
/sys/kernel/debug/clk/clk_summary says about how things ended up in 
practice, to see whether it's a case of the clock not being able to get 
close enough to the correct rate at all.

Robin.