https://bugzilla.kernel.org/show_bug.cgi?id=207593

Bug ID: 207593 Summary: [AMDGPU] The HDMI status(/sys) is not change after HDMI connector pull out Product: Drivers Version: 2.5 Kernel Version: 4.19.90 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: Video(DRI - non Intel) Assignee: drivers_video-dri@kernel-bugs.osdl.org Reporter: zhoubb.aaron@gmail.com Regression: No

Hi all:

I'm a newer about the amdgpu driver. I have a question about it. In my company, there are some experiments about HDMI hotplug. First, I introduce the lab environment: cpu: huawei kunpeng os: uos kernel: 4.19.90 video card: Radeon HD 700

the lab step is: 1, I connect the hdmi and vga with the expand mode; 2. I disconnect the hdmi connector, but the app display in the hdmi is not back to vga, and the mode is still expand mode.

I found when I disconnect the hdmi connector, the sys files about HDMI are keep the connection status. Such as the value of /sys/class/drm/card0-HDMI-A-1/status is connected, and I can read the edid file correctly. At this moment, I use I2C driver to read the edid via /dev/i2c-X. I can not get the edid value.

In kernel source ,I found the suspicious points in amdgpu_connector_dvi_detect() (amdgpu_connector.c)

In amdgpu_connector_dvi_detect() function, The hpd status was correctly through the amdgpu_display_hpd_sence(), but the ddc probe operation is successed via amdgpu_display_ddc_probe()

I am so confused.

Is it a normal behavior?

I have written a workaround patch to fix this problem.

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c index c770d73352a7..4809ceb56f5e 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c @@ -975,7 +975,7 @@ amdgpu_connector_dvi_detect(struct drm_connector *connector, bool force) const struct drm_encoder_helper_funcs *encoder_funcs; int r; enum drm_connector_status ret = connector_status_disconnected; - bool dret = false, broken_edid = false; + bool dret = false, broken_edid = false, unknown_status = false;

if (!drm_kms_helper_is_poll_worker()) { r = pm_runtime_get_sync(connector->dev->dev); @@ -990,7 +990,11 @@ amdgpu_connector_dvi_detect(struct drm_connector *connector, bool force)

if (amdgpu_connector->ddc_bus) dret = amdgpu_display_ddc_probe(amdgpu_connector, false); - if (dret) { + + if (!amdgpu_display_hpd_sense(adev, amdgpu_connector->hpd.hpd)) + unknown_status = true; + + if (dret && !unknown_status) { amdgpu_connector->detected_by_load = false; amdgpu_connector_free_edid(connector); amdgpu_connector_get_edid(connector);

Is it correctly？