Message-ID: <3161fa6a.93d0.19753f8c5e0.Coremail.andyshrk@163.com>
Date: Mon, 9 Jun 2025 17:15:01 +0800 (CST)
From: "Andy Yan" <andyshrk@....com>
To: "Diederik de Haas" <didi.debian@...ow.org>
Cc: "Piotr Zalewski" <pZ010001011111@...ton.me>, hjc@...k-chips.com,
	heiko@...ech.de, andy.yan@...k-chips.com,
	maarten.lankhorst@...ux.intel.com, mripard@...nel.org,
	tzimmermann@...e.de, airlied@...il.com, simona@...ll.ch,
	"Dang Huynh" <danct12@...eup.net>, dri-devel@...ts.freedesktop.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-rockchip@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re:Re: [PATCH drm-misc-next] rockchip/drm: vop2: don't check
 color_mgmt_changed in atomic_enable



Hi Diederik,

At 2025-06-08 20:53:37, "Diederik de Haas" <didi.debian@...ow.org> wrote:
>Hi Andy,
>
>On Sun Jun 8, 2025 at 2:10 PM CEST, Andy Yan wrote:
>> At 2025-06-08 19:08:50, "Diederik de Haas" <didi.debian@...ow.org> wrote:
>>>On Sat Jun 7, 2025 at 5:32 PM CEST, Piotr Zalewski wrote:
>>>> On Thursday, June 5th, 2025 at 10:13 PM, Diederik de Haas <didi.debian@...ow.org> wrote:
>>>>> Since kernel 6.14-rc1 I have the problem that visual output is no longer
>>>>> shown on my PineTab2 and a `git bisect` pointed to this patch/commit
>>>>> as the culprit. What is important to note is that `CONFIG_DRM=m` seems
>>>>> to be required as the problem does not occur with `CONFIG_DRM=y`.
>>>>> 
>>>>> Near the end of my bisect session, something interesting occurred.
>>>>> I was booted into a 'bad' kernel (ie no visual output) and when I
>>>>> started to build my final kernel, I closed the lid of the PineTab2 which
>>>>> made it go into suspend. When my final kernel was built, I opened the
>>>>> lid again, which made it resume, to transfer my final kernel to it.
>>>>> And much to my surprise, I then did have visual output.
>>>>> When I read the (below) commit message of the 'offending' commit, it may
>>>>> not be such a surprise after all.
>>>>> 
>>>>> I did try it on a Quartz64-B (also rk3566) and it did not have any issue
>>>>> (output via HDMI).
>>>>> I don't know what the cause for this issue is, hopefully you do.
>>>>
>>>> I tested and confirmed that this happens with drm=m but also in my case 
>>>> it happened when drm=y. After some testing I found out that at boot modeset
>>>
>>>Interesting that it also happened with drm=y.
>>>As you're more knowledgeable then I am with this, maybe look through
>>>https://lists.sr.ht/~diederik/pine64-discuss/<D9AM2OOLREO0.2JMAI42J06TW0@...ow.org>
>>>
>>>to see if you may spot something relevant?
>>>
>>>> happened twice and at short interval and since this patch allows for gamma 
>>>> LUT update regardless of color_mgmt_changed state this makes DSP CTRL GAMMA 
>>>> LUT EN bit to be unset twice too. It seems that VOP does not like it. I 
>>>
>>>Happy to see you found the cause :-)
>>>Do you happen to know why it was unset twice? That sounds suboptimal.
>>>But (IIUC) setting a bit to a value it already has causing issues,
>>>sounds surprising as well.
>>
>> I have conducted tests on both rk3566-box-demo (with drm set to y) and rk3568-lubancat-2 (with drm set to m), 
>> but I was unable to reproduce this issue. Could you two please share your kernel defconfig and the corresponding kernel startup logs? 
>> Additionally, both of my two boards tested with HDMI output. What kind of display interface does your board use for output?
>
>I wasn't able to reproduce this issue on my PINE64 Quartz-B (rk3566) 
>with HDMI output either, but the problem is present on a PineTab2 [1]
>(also rk3566) which uses a MIPI DSI connection to the display panel.
>
>Kernel config:
>https://paste.sr.ht/~diederik/aa747ed170aa01cc759fbe1ffd9cebe8c887b10b
>
>dmesg kernel 6.14-rc1:
>https://paste.sr.ht/~diederik/733fbf8bb7f6aee8b68cf5a652157d445462c24a
>
>dmesg kernel 6.14-rc1 with Piotr's patch:
>https://paste.sr.ht/~diederik/db1af672cfb611acbfbdf35adb6f170e5c38febc
>
>Both dmesg outputs contain a suspend-resume cycle.
>I'm using a USB Wi-Fi adapter for the wireless connection.
>
>[1] https://wiki.pine64.org/wiki/PineTab2
>
>Happy to provide more info and/or do some tests.

Can you apply the patch in the attachment, reproduce this issue(without Piotr's patch), 
and then provide me with a copy of the kernel log?

Thanks.

>
>Cheers,
>  Diederik
>
>>>> patched vop2_vp_dsp_lut_disable function so that dsp_ctrl is set only if 
>>>> GAMMA LUT EN bit is set. I checked that this also does not break the gamma 
>>>> lut functionality with emphasis on out-of/into suspend behavior.
>>>>
>>>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>>>> index d0f5fea15e21..7ddf311b38c6 100644
>>>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>>>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>>>> @@ -897,6 +897,9 @@ static void vop2_vp_dsp_lut_disable(struct vop2_video_port *vp)
>>>>  {
>>>>  	u32 dsp_ctrl = vop2_vp_read(vp, RK3568_VP_DSP_CTRL);
>>>>  
>>>> +	if ((dsp_ctrl & RK3568_VP_DSP_CTRL__DSP_LUT_EN) == 0)
>>>> +		return;
>>>> +
>>>>  	dsp_ctrl &= ~RK3568_VP_DSP_CTRL__DSP_LUT_EN;
>>>>  	vop2_vp_write(vp, RK3568_VP_DSP_CTRL, dsp_ctrl);
>>>>  }
>>>
>>>I built a kernel with 6.14-rc1 + this patch and can confirm the screen
>>>has output again :-)
>>>
>>>> I will wait with sending a patch because maybe Andy has something to add 
>>>> to this.
>>>
>>>Sounds like a plan. It could be that this issue surfaced an underlaying
>>>issue and if so, fixing that would be even better.

Download attachment "print_lut_0609_1710.patch" of type "application/octet-stream" (1223 bytes)

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