drm/amd/display: Add an hdmi_hpd_debounce_delay_ms module

[Why&How]
Right now, the HDMI HPD filter is enabled by default at 1500ms.

We want to disable it by default, as most modern displays with HDMI do
not require it for DPMS mode.

The HPD can instead be enabled as a driver parameter with a custom delay
value in ms (up to 5000ms).

Fixes: c918e75e1ed9 ("drm/amd/display: Add an HPD filter for HDMI")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4859
Signed-off-by: Ivan Lipski <ivan.lipski@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 6a681cd9034587fe3550868bacfbd639d1c6891f)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 9f9774f58ce1cb2dad797f3d969cab87bb0ad1ed..b20a06abb65dd72cad645b65c60a5bc91a3a479e 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -274,6 +274,8 @@ extern int amdgpu_rebar;
 extern int amdgpu_wbrf;
 extern int amdgpu_user_queue;
 
+extern uint amdgpu_hdmi_hpd_debounce_delay_ms;
+
 #define AMDGPU_VM_MAX_NUM_CTX                  4096
 #define AMDGPU_SG_THRESHOLD                    (256*1024*1024)
 #define AMDGPU_WAIT_IDLE_TIMEOUT_IN_MS         3000

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index 848e6b7db482d8e84a29fc23096aa11310d2a2a0..6ccb80e2d7c9b59e248ec8b9fa27602058858a23 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -247,6 +247,7 @@ int amdgpu_damage_clips = -1; /* auto */
 int amdgpu_umsch_mm_fwlog;
 int amdgpu_rebar = -1; /* auto */
 int amdgpu_user_queue = -1;
+uint amdgpu_hdmi_hpd_debounce_delay_ms;
 
 DECLARE_DYNDBG_CLASSMAP(drm_debug_classes, DD_CLASS_TYPE_DISJOINT_BITS, 0,
                        "DRM_UT_CORE",
@@ -1123,6 +1124,16 @@ module_param_named(rebar, amdgpu_rebar, int, 0444);
 MODULE_PARM_DESC(user_queue, "Enable user queues (-1 = auto (default), 0 = disable, 1 = enable, 2 = enable UQs and disable KQs)");
 module_param_named(user_queue, amdgpu_user_queue, int, 0444);
 
+/*
+ * DOC: hdmi_hpd_debounce_delay_ms (uint)
+ * HDMI HPD disconnect debounce delay in milliseconds.
+ *
+ * Used to filter short disconnect->reconnect HPD toggles some HDMI sinks
+ * generate while entering/leaving power save. Set to 0 to disable by default.
+ */
+MODULE_PARM_DESC(hdmi_hpd_debounce_delay_ms, "HDMI HPD disconnect debounce delay in milliseconds (0 to disable (by default), 1500 is common)");
+module_param_named(hdmi_hpd_debounce_delay_ms, amdgpu_hdmi_hpd_debounce_delay_ms, uint, 0644);
+
 /* These devices are not supported by amdgpu.
  * They are supported by the mach64, r128, radeon drivers
  */

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index fae88ce8327fa934638dc32ee39851ac019ed2ae..1ea5a250440f6076ae3af3f2130fb71256e53740 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -8947,9 +8947,18 @@ void amdgpu_dm_connector_init_helper(struct amdgpu_display_manager *dm,
        mutex_init(&aconnector->hpd_lock);
        mutex_init(&aconnector->handle_mst_msg_ready);
 
-       aconnector->hdmi_hpd_debounce_delay_ms = AMDGPU_DM_HDMI_HPD_DEBOUNCE_MS;
-       INIT_DELAYED_WORK(&aconnector->hdmi_hpd_debounce_work, hdmi_hpd_debounce_work);
-       aconnector->hdmi_prev_sink = NULL;
+       /*
+        * If HDMI HPD debounce delay is set, use the minimum between selected
+        * value and AMDGPU_DM_MAX_HDMI_HPD_DEBOUNCE_MS
+        */
+       if (amdgpu_hdmi_hpd_debounce_delay_ms) {
+               aconnector->hdmi_hpd_debounce_delay_ms = min(amdgpu_hdmi_hpd_debounce_delay_ms,
+                                                            AMDGPU_DM_MAX_HDMI_HPD_DEBOUNCE_MS);
+               INIT_DELAYED_WORK(&aconnector->hdmi_hpd_debounce_work, hdmi_hpd_debounce_work);
+               aconnector->hdmi_prev_sink = NULL;
+       } else {
+               aconnector->hdmi_hpd_debounce_delay_ms = 0;
+       }
 
        /*
         * configure support HPD hot plug connector_>polled default value is 0

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
index bd0403005f370e11e65274a5cb114c0543c702a0..beb0d04d3e68273d9a386533d51abef3380bbc26 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h
@@ -59,7 +59,10 @@
 
 #define AMDGPU_HDR_MULT_DEFAULT (0x100000000LL)
 
-#define AMDGPU_DM_HDMI_HPD_DEBOUNCE_MS 1500
+/*
+ * Maximum HDMI HPD debounce delay in milliseconds
+ */
+#define AMDGPU_DM_MAX_HDMI_HPD_DEBOUNCE_MS 5000
 /*
 #include "include/amdgpu_dal_power_if.h"
 #include "amdgpu_dm_irq.h"