[PATCH v3 1/4] 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.

Bspec: 68849
Fixes: 9dc619680de4 ("drm/i915/display: Add function to configure LFPS sending")
Signed-off-by: Jouni Högander <jouni.hogan...@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.so...@intel.com>
---
 drivers/gpu/drm/i915/display/intel_cx0_phy.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 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..2b0305bb04cd 100644
--- a/drivers/gpu/drm/i915/display/intel_cx0_phy.c
+++ b/drivers/gpu/drm/i915/display/intel_cx0_phy.c
@@ -3240,11 +3240,10 @@ void intel_lnl_mac_transmit_lfps(struct intel_encoder 
*encoder,
 {
        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);
        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;
 
        for (i = 0; i < 4; i++) {
@@ -3256,8 +3255,7 @@ 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