Re: [PATCH 6.12.y] drm/i915/dsi: Use TRANS_DDI_FUNC_CTL's own port width macro

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
ℹ️ Patch is missing in 6.13.y (ignore if backport was sent)
⚠️ Commit missing in all newer stable branches

The upstream commit SHA1 provided is correct: 879f70382ff3e92fc854589ada3453e3f5f5b601

Status in newer kernel trees:
6.13.y | Present (different SHA1: d636772d1796)
6.6.y | Not found

Note: The patch differs from the upstream commit:
---
1:  879f70382ff3e ! 1:  616483933e167 drm/i915/dsi: Use TRANS_DDI_FUNC_CTL's own port width macro
    @@ Metadata
      ## Commit message ##
         drm/i915/dsi: Use TRANS_DDI_FUNC_CTL's own port width macro
     
    +    commit 879f70382ff3e92fc854589ada3453e3f5f5b601 upstream.
    +
         The format of the port width field in the DDI_BUF_CTL and the
         TRANS_DDI_FUNC_CTL registers are different starting with MTL, where the
         x3 lane mode for HDMI FRL has a different encoding in the two registers.
    @@ Commit message
         Link: https://patchwork.freedesktop.org/patch/msgid/20250214142001.552916-2-imre.deak@intel.com
         (cherry picked from commit 76120b3a304aec28fef4910204b81a12db8974da)
         Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
    +    (cherry picked from commit 879f70382ff3e92fc854589ada3453e3f5f5b601)
    +    [Imre: Rebased on v6.12.y, due to upstream API changes in
    +     intel_de_read(), TRANS_DDI_FUNC_CTL()]
    +    Signed-off-by: Imre Deak <imre.deak@intel.com>
     
      ## drivers/gpu/drm/i915/display/icl_dsi.c ##
     @@ drivers/gpu/drm/i915/display/icl_dsi.c: gen11_dsi_configure_transcoder(struct intel_encoder *encoder,
      		/* select data lane width */
    - 		tmp = intel_de_read(display,
    - 				    TRANS_DDI_FUNC_CTL(display, dsi_trans));
    + 		tmp = intel_de_read(dev_priv,
    + 				    TRANS_DDI_FUNC_CTL(dev_priv, dsi_trans));
     -		tmp &= ~DDI_PORT_WIDTH_MASK;
     -		tmp |= DDI_PORT_WIDTH(intel_dsi->lane_count);
     +		tmp &= ~TRANS_DDI_PORT_WIDTH_MASK;
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.12.y       |  Success    |  Success   |