[PATCH 06/23] drm/i915/dp: Fix readback for target_rr in Adaptive Sync SDP

Ankit Nautiyal
2026-04-02T08:19:53Z

Correct the bit-shift logic to properly readback the 10 bit target_rr from
DB3 and DB4.

v2: Align the style with readback for vtotal. (Ville)

Fixes: 12ea89291603 ("drm/i915/dp: Add Read/Write support for Adaptive Sync SDP")
Cc: Mitul Golani <mitulkumar.ajitkumar.golani@intel.com>
Cc: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
drivers/gpu/drm/i915/display/intel_dp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 602efaf500bd..49eeb35973a1 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -5298,7 +5298,7 @@ int intel_dp_as_sdp_unpack(struct drm_dp_as_sdp *as_sdp,
as_sdp->length = sdp->sdp_header.HB3 & DP_AS_SDP_LENGTH_MASK;
as_sdp->mode = sdp->db[0] & DP_AS_SDP_OPERATION_MODE_MASK;
as_sdp->vtotal = (sdp->db[2] << 8) | sdp->db[1];
- as_sdp->target_rr = (u64)sdp->db[3] | ((u64)sdp->db[4] & 0x3);
+ as_sdp->target_rr = ((sdp->db[4] & 0x3) << 8) | sdp->db[3];
as_sdp->target_rr_divider = sdp->db[4] & 0x20 ? true : false;

return 0;
--
2.45.2