Quoting Dnyaneshwar Bhadane (2025-09-09 06:45:35-03:00)
>On PTL, no combo PHY is connected to PORT B. However, PORT B can
>still be used for Type-C and will utilize the C20 PHY for eDP
>over Type-C. In such configurations, VBTs also enumerate PORT B.
>
>This leads to issues where PORT B is incorrectly identified as using the
>C10 PHY, due to the assumption that returning true for PORT B in
>intel_encoder_is_c10phy() would not cause problems.
>
>From PTL's perspective, only PORT A/PHY A uses the C10 PHY.
>
>Update the helper intel_encoder_is_c10phy() to return true only for
>PORT A/PHY on PTL.
>
I think we need a "Fixes" tag here.
Fixes: 9d10de78a37f ("drm/i915/wcl: C10 phy connected to port A and B")
>Bspec: 72571,73944
>Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhad...@intel.com>
>Reviewed-by: Ankit Nautiyal <ankit.k.nauti...@intel.com>
>---
> drivers/gpu/drm/i915/display/intel_cx0_phy.c | 9 ++-------
> 1 file changed, 2 insertions(+), 7 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>index 801235a5bc0a..33963ad14cfa 100644
>--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
>@@ -39,13 +39,8 @@ bool intel_encoder_is_c10phy(struct intel_encoder *encoder)
> struct intel_display *display = to_intel_display(encoder);
> enum phy phy = intel_encoder_to_phy(encoder);
>
>- /* PTL doesn't have a PHY connected to PORT B; as such,
>- * there will never be a case where PTL uses PHY B.
>- * WCL uses PORT A and B with the C10 PHY.
>- * Reusing the condition for WCL and extending it for PORT B
>- * should not cause any issues for PTL.
>- */
>- if (display->platform.pantherlake && phy < PHY_C)
>+ if ((display->platform.pantherlake && phy == PHY_A) ||
>+ ((DISPLAY_VERx100(display) == 3002) && phy == PHY_B))
This is usually a property of the SoC and not the display IP. So, we
probably want to know that we are on WCL rather than display version
3002, which could theoretically be re-used in other platforms with
different display PHY(s).
Also, as side note, there are many superfluous parentheses in the
condition. I think only the one for the if-condition is necessary.
--
Gustavo Sousa
> return true;
>
> if ((display->platform.lunarlake || display->platform.meteorlake) &&
> phy < PHY_C)
>--
>2.51.0
>
