Re: [PATCH v6] drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Missing ATOM_ENCODER_CMD_DP_VIDEO_OFF for iMac11,1 in DPMS disable path
--

--- Patch [1]: [PATCH v6] drm/radeon: fix internal display on iMac11, 1  (RV770/DCE3.1) ---
commit 6714fa0de0a69a7e28cd2cf7fe610715f038e79d
Author: Gilles Risch <gilles.risch@gmail.com>
drm/radeon: fix internal display on iMac11, 1 (RV770/DCE3.1)

This commit adds a DMI quirk to route the iMac11,1 internal display
through Link B of the DIG encoder. It also sets the FRAC_FB_DIV PLL flag
and enables DP_VIDEO_ON explicitly for this hardware to fix a blank screen
issue.

> diff --git a/drivers/gpu/drm/radeon/atombios_encoders.c b/drivers/gpu/drm/radeon/atombios_encoders.c
> --- a/drivers/gpu/drm/radeon/atombios_encoders.c
> +++ b/drivers/gpu/drm/radeon/atombios_encoders.c

[ ... ]

> @@ -1707,7 +1707,7 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
>  		if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector) {
>  			/* DP_SET_POWER_D0 is set in radeon_dp_link_train */
>  			radeon_dp_link_train(encoder, connector);
> -			if (ASIC_IS_DCE4(rdev))
> +			if (ASIC_IS_DCE4(rdev) || dmi_match(DMI_PRODUCT_NAME, "iMac11,1"))
>  				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_ON, 0);
>  		}

[Severity: Medium]
Should the corresponding disable paths (standby, suspend, off) also
include the iMac11,1 DMI check for turning the video off?

Later in radeon_atom_encoder_dpms_dig(), the ATOM_ENCODER_CMD_DP_VIDEO_OFF
command is only sent if ASIC_IS_DCE4(rdev):

    case DRM_MODE_DPMS_STANDBY:
    case DRM_MODE_DPMS_SUSPEND:
    case DRM_MODE_DPMS_OFF:

        if (ASIC_IS_DCE4(rdev)) {
            if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
                atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
        }

Does the iMac11,1 (which is DCE3.1) need ATOM_ENCODER_CMD_DP_VIDEO_OFF
sent here to properly stop the stream before the link is disabled?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260817004326.3192-1-gilles.risch@gmail.com?part=1