[PATCH v2] drm/rockchip: vop2: Add mode valid callback for crtc

[Andy Yan]

Hello Sebastian,

At 2026-01-19 07:43:35, "Sebastian Reichel" <sebastian.reichel at collabora.com> wrote:
>Hi,
>
>On Sat, Jan 17, 2026 at 10:07:30AM +0800, Andy Yan wrote:
>> From: Andy Yan <andy.yan at rock-chips.com>
>> 
>> The different Video Ports support different maximum resolutions.
>> Reject resolutions that are not supported by a specific VP.
>> 
>> Only the output width is checked because the hardware itself does
>> not have a hard output height limit.
>> 
>> Filter the mode that can't output by the VP/crtc.
>> 
>> Signed-off-by: Andy Yan <andy.yan at rock-chips.com>
>> 
>> ---
>
>A common RK3576 setup is VP0 mapped to HDMI and VP1 mapped to USB-C
>DP AltMode. Since RK3576 VP1 only supports 2.5K, this can easily
>become relevant when connecting a 4K screen via USB-C DP AltMode.
>I've tested that this patch properly drops all unsupported modes
>based on the resolution.
>
>Further checks will be needed to ensure the bandwidth requirements
>are also met (e.g. RK3576 VP1 only supports 2.5K at 60Hz, so 2.5K at 120Hz
>should be marked as BAD). I think the bandwidth check should be a
>separate patch, but thought it might be worth mentioning here in
>case somebody stumbles over it.

Yes, I also think it's better to do by a separate patch,  because we should add
more detail dclk description for every VP.  I will do it after this patch get merged.

>
>Anyways:
>
>Reviewed-by: Sebastian Reichel <sebastian.reichel at collabora.com>
>Tested-by: Sebastian Reichel <sebastian.reichel at collabora.com> # Sige5
>
>Greetings,
>
>-- Sebastian
>
>> 
>> Changes in v2:
>> - Add more detailed commit message
>> 
>>  drivers/gpu/drm/rockchip/rockchip_drm_vop2.c | 12 ++++++++++++
>>  1 file changed, 12 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>> index 498df0ce4680..74fba29bfff3 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_vop2.c
>> @@ -1439,6 +1439,17 @@ static void vop2_crtc_disable_vblank(struct drm_crtc *crtc)
>>  	vop2_crtc_disable_irq(vp, VP_INT_FS_FIELD);
>>  }
>>  
>> +static enum drm_mode_status vop2_crtc_mode_valid(struct drm_crtc *crtc,
>> +						 const struct drm_display_mode *mode)
>> +{
>> +	struct vop2_video_port *vp = to_vop2_video_port(crtc);
>> +
>> +	if (mode->hdisplay > vp->data->max_output.width)
>> +		return MODE_BAD_HVALUE;
>> +
>> +	return MODE_OK;
>> +}
>> +
>>  static bool vop2_crtc_mode_fixup(struct drm_crtc *crtc,
>>  				 const struct drm_display_mode *mode,
>>  				 struct drm_display_mode *adj_mode)
>> @@ -1884,6 +1895,7 @@ static void vop2_crtc_atomic_flush(struct drm_crtc *crtc,
>>  
>>  static const struct drm_crtc_helper_funcs vop2_crtc_helper_funcs = {
>>  	.mode_fixup = vop2_crtc_mode_fixup,
>> +	.mode_valid = vop2_crtc_mode_valid,
>>  	.atomic_check = vop2_crtc_atomic_check,
>>  	.atomic_begin = vop2_crtc_atomic_begin,
>>  	.atomic_flush = vop2_crtc_atomic_flush,
>> -- 
>> 2.43.0
>> 
>> base-commit: 1613a67b5360d6ff78f62143a1cf123414a1b4d9
>> branch: rk3576-dp-upstream
>>