Re: [PATCH 6.6.y] drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Provided upstream commit SHA1 does not match found commit

The claimed upstream commit SHA1 (b2ecdabe46d23db275f94cd7c46ca414a144818b) was not found.
However, I found a matching commit: 166ce267ae3f96e439d8ccc838e8ec4d8b4dab73

Note: The patch differs from the upstream commit:
---
1:  166ce267ae3f9 ! 1:  5dcc143132529 drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL
    @@ Metadata
      ## Commit message ##
         drm/i915/ddi: Fix HDMI port width programming in DDI_BUF_CTL
     
    +    commit b2ecdabe46d23db275f94cd7c46ca414a144818b upstream.
    +
         Fix the port width programming in the DDI_BUF_CTL register on MTLP+,
         where this had an off-by-one error.
     
    @@ Commit message
         Link: https://patchwork.freedesktop.org/patch/msgid/20250214142001.552916-3-imre.deak@intel.com
         (cherry picked from commit b2ecdabe46d23db275f94cd7c46ca414a144818b)
         Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
    +    (cherry picked from commit 166ce267ae3f96e439d8ccc838e8ec4d8b4dab73)
    +    [Imre: Rebased on v6.6.y, due to upstream API changes for
    +     XELPDP_PORT_BUF_CTL1() and addition of the XE2LPD_DDI_BUF_D2D_LINK_ENABLE flag]
    +    Signed-off-by: Imre Deak <imre.deak@intel.com>
     
      ## drivers/gpu/drm/i915/display/intel_ddi.c ##
    -@@ drivers/gpu/drm/i915/display/intel_ddi.c: static void intel_ddi_enable_hdmi(struct intel_atomic_state *state,
    - 		intel_de_rmw(dev_priv, XELPDP_PORT_BUF_CTL1(dev_priv, port),
    +@@ drivers/gpu/drm/i915/display/intel_ddi.c: static void intel_enable_ddi_hdmi(struct intel_atomic_state *state,
    + 		intel_de_rmw(dev_priv, XELPDP_PORT_BUF_CTL1(port),
      			     XELPDP_PORT_WIDTH_MASK | XELPDP_PORT_REVERSAL, port_buf);
      
     -		buf_ctl |= DDI_PORT_WIDTH(lane_count);
     +		buf_ctl |= DDI_PORT_WIDTH(crtc_state->lane_count);
    - 
    - 		if (DISPLAY_VER(dev_priv) >= 20)
    - 			buf_ctl |= XE2LPD_DDI_BUF_D2D_LINK_ENABLE;
    + 	} else if (IS_ALDERLAKE_P(dev_priv) && intel_phy_is_tc(dev_priv, phy)) {
    + 		drm_WARN_ON(&dev_priv->drm, !intel_tc_port_in_legacy_mode(dig_port));
    + 		buf_ctl |= DDI_BUF_CTL_TC_PHY_OWNERSHIP;
     
      ## drivers/gpu/drm/i915/i915_reg.h ##
     @@ drivers/gpu/drm/i915/i915_reg.h: enum skl_power_gate {
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |