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From:   Abhinav Kumar <quic_abhinavk@quicinc.com>
To:     <freedreno@lists.freedesktop.org>, Rob Clark <robdclark@gmail.com>,
        Abhinav Kumar <quic_abhinavk@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Sean Paul <sean@poorly.run>, David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>
CC:     <dri-devel@lists.freedesktop.org>, <quic_jesszhan@quicinc.com>,
        <swboyd@chromium.org>, <dianders@chromium.org>,
        <linux-arm-msm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] drm/msm/dp: add module parameter for PSR
Date:   Thu, 27 Apr 2023 16:28:47 -0700
Message-ID: <20230427232848.5200-1-quic_abhinavk@quicinc.com>
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Precedence: bulk

On sc7280 where eDP is the primary display, PSR is causing
IGT breakage even for basic test cases like kms_atomic and
kms_atomic_transition. Most often the issue starts with below
stack so providing that as reference

Call trace:
 dpu_encoder_assign_crtc+0x64/0x6c
 dpu_crtc_enable+0x188/0x204
 drm_atomic_helper_commit_modeset_enables+0xc0/0x274
 msm_atomic_commit_tail+0x1a8/0x68c
 commit_tail+0xb0/0x160
 drm_atomic_helper_commit+0x11c/0x124
 drm_atomic_commit+0xb0/0xdc
 drm_atomic_connector_commit_dpms+0xf4/0x110
 drm_mode_obj_set_property_ioctl+0x16c/0x3b0
 drm_connector_property_set_ioctl+0x4c/0x74
 drm_ioctl_kernel+0xec/0x15c
 drm_ioctl+0x264/0x408
 __arm64_sys_ioctl+0x9c/0xd4
 invoke_syscall+0x4c/0x110
 el0_svc_common+0x94/0xfc
 do_el0_svc+0x3c/0xb0
 el0_svc+0x2c/0x7c
 el0t_64_sync_handler+0x48/0x114
 el0t_64_sync+0x190/0x194
---[ end trace 0000000000000000 ]---
[drm-dp] dp_ctrl_push_idle: PUSH_IDLE pattern timedout

Other basic use-cases still seem to work fine hence add a
a module parameter to allow toggling psr enable/disable till
PSR related issues are hashed out with IGT.

Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
---
 drivers/gpu/drm/msm/dp/dp_display.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
index 628b0e248db6..dba43167de66 100644
--- a/drivers/gpu/drm/msm/dp/dp_display.c
+++ b/drivers/gpu/drm/msm/dp/dp_display.c
@@ -28,6 +28,10 @@
 #include "dp_audio.h"
 #include "dp_debug.h"
 
+static bool psr_enabled = false;
+module_param(psr_enabled, bool, 0);
+MODULE_PARM_DESC(psr_enabled, "enable PSR for eDP and DP displays");
+
 #define HPD_STRING_SIZE 30
 
 enum {
@@ -407,7 +411,7 @@ static int dp_display_process_hpd_high(struct dp_display_private *dp)
 
 	edid = dp->panel->edid;
 
-	dp->dp_display.psr_supported = dp->panel->psr_cap.version;
+	dp->dp_display.psr_supported = dp->panel->psr_cap.version && psr_enabled;
 
 	dp->audio_supported = drm_detect_monitor_audio(edid);
 	dp_panel_handle_sink_request(dp->panel);
-- 
2.40.1