[PATCH] drm/i915/display: Write PHY_CMN1_CONTROL only when using AUXLess ALPM

[Jouni Högander]

We are seeing "dmesg-warn/abort - *ERROR* PHY * failed after 3 retries"
since we started configuring LFPS sending. According to Bspec Configuring
LFPS sending is needed only when using AUXLess ALPM. This patch avoids
these failures by configuring LFPS sending only when using AUXLess ALPM.

Fixes: 9dc619680de4 ("drm/i915/display: Add function to configure LFPS sending")
Signed-off-by: Jouni Högander <jouni.hogan...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_cx0_phy.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_cx0_phy.c 
b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
index ed8e640b96b0..9cfc3187aeab 100644
--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
@@ -3239,14 +3239,14 @@ void intel_lnl_mac_transmit_lfps(struct intel_encoder 
*encoder,
                                 const struct intel_crtc_state *crtc_state)
 {
        struct intel_display *display = to_intel_display(encoder);
-       u8 owned_lane_mask = intel_cx0_get_owned_lane_mask(encoder);
-       bool enable = intel_alpm_is_alpm_aux_less(enc_to_intel_dp(encoder),
-                                                 crtc_state);
+       u8 owned_lane_mask;
        int i;
 
-       if (DISPLAY_VER(display) < 20)
+       if (DISPLAY_VER(display) < 20 ||
+           !intel_alpm_is_alpm_aux_less(enc_to_intel_dp(encoder), crtc_state))
                return;
 
+       owned_lane_mask = intel_cx0_get_owned_lane_mask(encoder);
        for (i = 0; i < 4; i++) {
                int tx = i % 2 + 1;
                u8 lane_mask = i < 2 ? INTEL_CX0_LANE0 : INTEL_CX0_LANE1;
@@ -3256,8 +3256,7 @@ void intel_lnl_mac_transmit_lfps(struct intel_encoder 
*encoder,
 
                intel_cx0_rmw(encoder, lane_mask, PHY_CMN1_CONTROL(tx, 0),
                              CONTROL0_MAC_TRANSMIT_LFPS,
-                             enable ? CONTROL0_MAC_TRANSMIT_LFPS : 0,
-                             MB_WRITE_COMMITTED);
+                             CONTROL0_MAC_TRANSMIT_LFPS, MB_WRITE_COMMITTED);
        }
 }
 
-- 
2.43.0