Re: The inherent defect of the AMDGPU driver about hotplug
Yes, I agree.
On Tue, Jun 16, 2020 at 3:08 AM Alex Deucher wrote:
>
> On Mon, Jun 15, 2020 at 5:30 AM Aaron Chou wrote:
> >
> > About one month ago, I have asked a question about HDMI hotplug, the link
> > is:
> >
> > https://gitlab.freedesktop.org/drm/amd/-/issues/1135#note_492460
> >
> > And I have put one patch to fix this, as follows:
> >
> > 39 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > 40 index f355d9a752d2..ee657db9a228 100644
> > 41 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > 42 +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > 43 @@ -973,7 +973,7 @@ amdgpu_connector_dvi_detect(struct
> > drm_connector *connector, bool force)
> > 44 const struct drm_encoder_helper_funcs *encoder_funcs;
> > 45 int r;
> > 46 enum drm_connector_status ret =
> > connector_status_disconnected;
> > 47 - bool dret = false, broken_edid = false;
> > 48 + bool dret = false, broken_edid = false, undefined_flag =
> > false;
> > 49
> > 50 if (!drm_kms_helper_is_poll_worker()) {
> > 51 r = pm_runtime_get_sync(connector->dev->dev);
> > 52 @@ -988,7 +988,12 @@ amdgpu_connector_dvi_detect(struct
> > drm_connector *connector, bool force)
> > 53
> > 54 if (amdgpu_connector->ddc_bus)
> > 55 dret = amdgpu_display_ddc_probe(amdgpu_connector,
> > false);
> > 56 - if (dret) {
> > 57 +
> > 58 + /* Check the HDMI HPD pin status again */
> > 59 + if (!amdgpu_display_hpd_sense(adev,
> > amdgpu_connector->hpd.hpd))
> > 60 + undefined_flag = true;
> > 61 +
> > 62 + if (dret && !undefined_flag) {
> > 63 amdgpu_connector->detected_by_load = false;
> > 64 amdgpu_connector_free_edid(connector);
> > 65 amdgpu_connector_get_edid(connector);
> >
> > Maybe the fix is sloppy, so I write the another patch:
> >
> > 16 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > 17 index c770d73352a7..bb59ebc9a6c8 100644
> > 18 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > 19 +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > 20 @@ -991,6 +991,7 @@ amdgpu_connector_dvi_detect(struct
> > drm_connector *connector, bool force)
> > 21 if (amdgpu_connector->ddc_bus)
> > 22 dret = amdgpu_display_ddc_probe(amdgpu_connector,
> > false);
> > 23 if (dret) {
> > 24 + schedule_work(>hotplug_work);
> > 25 amdgpu_connector->detected_by_load = false;
> > 26 amdgpu_connector_free_edid(connector);
> > 27 amdgpu_connector_get_edid(connector);
> >
> > Which is better, or neither？
>
> As per the last discussion:
>
> "This is the part I don't understand. The logic already checks the HPD
> status in amdgpu_connector_check_hpd_status_unchanged(). Does it
> still report connected at that point? After that it tries to read the
> EDID in amdgpu_display_ddc_probe(). If the monitor is disconnected,
> there should be no EDID so dret should be false. We should try and
> figure out why the first HPD check reports connected and the EDID
> probe returns true."
>
> There is already an HPD probe in the current logic. We should try and
> understand why we need a second one rather than just adding one. Does
> a delay at the top of that function help?
>
> Alex
>
> >
> > --
> > Regards,
> > Aaron
> > ___
> > amd-gfx mailing list
> > amd-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
___
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
The inherent defect of the AMDGPU driver about hotplug
About one month ago, I have asked a question about HDMI hotplug, the link is:
https://gitlab.freedesktop.org/drm/amd/-/issues/1135#note_492460
And I have put one patch to fix this, as follows:
39 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
40 index f355d9a752d2..ee657db9a228 100644
41 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
42 +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
43 @@ -973,7 +973,7 @@ amdgpu_connector_dvi_detect(struct
drm_connector *connector, bool force)
44 const struct drm_encoder_helper_funcs *encoder_funcs;
45 int r;
46 enum drm_connector_status ret =
connector_status_disconnected;
47 - bool dret = false, broken_edid = false;
48 + bool dret = false, broken_edid = false, undefined_flag =
false;
49
50 if (!drm_kms_helper_is_poll_worker()) {
51 r = pm_runtime_get_sync(connector->dev->dev);
52 @@ -988,7 +988,12 @@ amdgpu_connector_dvi_detect(struct
drm_connector *connector, bool force)
53
54 if (amdgpu_connector->ddc_bus)
55 dret = amdgpu_display_ddc_probe(amdgpu_connector,
false);
56 - if (dret) {
57 +
58 + /* Check the HDMI HPD pin status again */
59 + if (!amdgpu_display_hpd_sense(adev,
amdgpu_connector->hpd.hpd))
60 + undefined_flag = true;
61 +
62 + if (dret && !undefined_flag) {
63 amdgpu_connector->detected_by_load = false;
64 amdgpu_connector_free_edid(connector);
65 amdgpu_connector_get_edid(connector);
Maybe the fix is sloppy, so I write the another patch:
16 diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
17 index c770d73352a7..bb59ebc9a6c8 100644
18 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
19 +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
20 @@ -991,6 +991,7 @@ amdgpu_connector_dvi_detect(struct
drm_connector *connector, bool force)
21 if (amdgpu_connector->ddc_bus)
22 dret = amdgpu_display_ddc_probe(amdgpu_connector,
false);
23 if (dret) {
24 + schedule_work(>hotplug_work);
25 amdgpu_connector->detected_by_load = false;
26 amdgpu_connector_free_edid(connector);
27 amdgpu_connector_get_edid(connector);
Which is better, or neither？
--
Regards,
Aaron
___
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
Re: [PATCH] drm/admgpu: check HDMI HPD status after ddc probe
On Sat, May 9, 2020 at 9:35 PM Alex Deucher wrote:
>
> On Sat, May 9, 2020 at 1:48 AM Binbin Zhou wrote:
> >
> > Now, we check the presence of the EDID to determine if there is a monitor
> > present.
> >
> > DVI-I connectors have both analog and digital encoders and the HPD pin
> > is only reliable on the digital part.
> >
> > But when I pull out the Radeon HD8570's HDMI connector, the HDMI status
> > in system is still perform connected.
> >
> > asd@asd-PC:~$ cat /sys/class/drm/card0-HDMI-A-1/status
> > connected
> >
> > At this moment, if I want to read the EDID by /dev/i2c-X with I2C
> > driver, there is no EDID can be read.
> >
> > Dmesg witha drm.debug=0x6, we can find the following message:
> >
> > [drm:drm_helper_hpd_irq_event] [CONNECTOR:41:HDMI-A-1] status
> > updated from connected to connected
> >
> > Based on the appearance, I thought to check the HPD status again, because
> > the HPD status is perform disconnected, after amdgpu_display_ddc_probe().
> > If the amdgpu_display_hpd_sense() return false, I think the HDMI connector
> > status is undefined, and just return disconnected simply.
> >
> > I'm not sure if it happened to other AMD cards.
>
> This is the part I don't understand. The logic already checks the HPD
> status in amdgpu_connector_check_hpd_status_unchanged(). Does it
> still report connected at that point? After that it tires to read the
> EDID in amdgpu_display_ddc_probe(). If the monitor is disconnected,
> there should be no EDID so dret should be false. We should try and
> figure out why the first HPD check reports connected and the EDID
> probe returns true.
>
> Alex
Emm.
I have tried with Radeon driver, it is the same.
And In the Mint system, I find if I pick out the HDMI connector, I can
see the status is still connected,
At the moment, If I do the xrandr command or open the Setting->Display
application, the HDMI status will refresh to disconnected.
The operation means to detect the display again.
Does the phenomenon meet the expectation？
Regards.
Aaron.
>
> >
> > Signed-off-by: Binbin Zhou
> > ---
> > drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c | 9 +++--
> > 1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > index f355d9a752d2..ee657db9a228 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> > @@ -973,7 +973,7 @@ 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, undefined_flag = false;
> >
> > if (!drm_kms_helper_is_poll_worker()) {
> > r = pm_runtime_get_sync(connector->dev->dev);
> > @@ -988,7 +988,12 @@ 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) {
> > +
> > + /* Check the HDMI HPD pin status again */
> > + if (!amdgpu_display_hpd_sense(adev, amdgpu_connector->hpd.hpd))
> > + undefined_flag = true;
> > +
> > + if (dret && !undefined_flag) {
> > amdgpu_connector->detected_by_load = false;
> > amdgpu_connector_free_edid(connector);
> > amdgpu_connector_get_edid(connector);
> > --
> > 2.17.1
> >
> > ___
> > amd-gfx mailing list
> > amd-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
___
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
A curious phenomenon in HDMI hotplug.
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.
Best Wishes！
Aaron.
___
amd-gfx mailing list
amd-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/amd-gfx
