** Description changed:
+ [Impact]
+
+ * In Ubuntu 20.04 (which using Xorg with proprietary nvidia driver), in some
cases, the nvidia driver will probe later than launching gdm.
+ * If above race condition happens in iGPU + nvidia cases and monitor
connects to dGPU, which will cause gdm starts with wayland as opposed to Xorg.
Which may lead the monitor stuck in black-screen or boot LOGO.
+
+ [Test Plan]
+
+ * The environment:
+ 1. A desktop or workstation which containing an iGPU.
+ 2. Plug a nvidia graphic card to the system and installing proprietary
+ nvidia driver (470 in my case)
+ 3. Attach a monitor to dGPU and leave iGPU connect to nothing.
+ (in my test environment, there is the other ethernet card and TBT4 cards)
+ * Setup a cronjob,
+ e.g. @reboot /home/u/test.sh
+ * Have a test script in something like /home/u/test.sh as
+
+ #!/bin/bash
+
+ sleep 20
+ count="$(cat /home/u/count)"
+ count=$((count+1))
+ echo $count | tee /home/u/count
+ journalctl -b | grep -q -i wayland || sudo reboot
+
+ * the system will probably stuck in black-screen or boot LOGO.
+ * Before applying the fix, the fail rate is 6/24 (fail 6 time in 24 runs).
+ * After applying the fix, it got pass within 90 reboot cycles.
+
+ [Where problems could occur]
+ * The patch checkes device/boot_vga with tag "master-of-seat". If a system
without any GPU as boot_vga then it will fall in infinite loop.
+ * I tried to detach all monitors from the system and the boot_vga still
exist (default to use iGPU, the first device found during initialization)
+ * I don't think they will a case which boot_vga doesn't exist in this moment
because:
+ In drivers/gpu/vga/vgaarb.c (linux package)
+ vga_arb_select_default_device() has a fallback function to determine the
boot_vga device to prevent firmware doesn't pass correct efifb to linux-kernel.
+
+ ---
+
Test environment/steps:
1. A desktop or workstation which containing an iGPU.
2. Plug a nvidia graphic card to the system and installing proprietary nvidia
driver (470 in my case)
3. Attach a monitor to dGPU and leave iGPU connect to nothing.
(in my test environment, there is the other ethernet card and TBT4 cards)
4. Reboot system.
Based on:
$ cat /lib/udev/rules.d/61-gdm.rules
# disable Wayland on Hi1710 chipsets
ATTR{vendor}=="0x19e5", ATTR{device}=="0x1711",
RUN+="/usr/lib/gdm3/gdm-disable-wayland"
# disable Wayland when using the proprietary nvidia driver
DRIVER=="nvidia", RUN+="/usr/lib/gdm3/gdm-disable-wayland"
It will disable wayland by default if proprietary nvidia driver load.
But in some race condition cases, the nvidia probe is later than gnome
launches. (The fail rate is 6/24.)
Thus, ubuntu-gdm has a fix for Bug#1794280 to add
"ExecStartPre=@libexecdir@/gdm-wait-for-drm".
-
- The gdm-wait-for-drm is intend to make sure all drm udev devices enumerated
before launching gdm.
+ The gdm-wait-for-drm is intend to make sure all drm udev devices
+ enumerated before launching gdm.
It rely on at least one "master-of-seat" graphic card for gdm but it's not
rigorous enough.
Since most of graphic cards are own "master-of-seat"[1].
In my case, it detects the iGPU is probed but dGPU.
However, the display is attached to dGPU.
We need to make sure the targeted gpu (connecting to monitor) is probe
before launching gdm.
[1] https://www.freedesktop.org/wiki/Software/systemd/multiseat/
/lib/udev/rules.d/71-seat.rules
/lib/udev/rules.d/71-nvidia.rules
** Description changed:
[Impact]
- * In Ubuntu 20.04 (which using Xorg with proprietary nvidia driver), in some
cases, the nvidia driver will probe later than launching gdm.
- * If above race condition happens in iGPU + nvidia cases and monitor
connects to dGPU, which will cause gdm starts with wayland as opposed to Xorg.
Which may lead the monitor stuck in black-screen or boot LOGO.
+ * In Ubuntu 20.04 (which using Xorg with proprietary nvidia driver), in some
cases, the nvidia driver will probe later than launching gdm.
+ * If above race condition happens in iGPU + nvidia cases and monitor
connects to dGPU, which will cause gdm starts with wayland as opposed to Xorg.
Which may lead the monitor stuck in black-screen or boot LOGO.
[Test Plan]
- * The environment:
- 1. A desktop or workstation which containing an iGPU.
- 2. Plug a nvidia graphic card to the system and installing proprietary
- nvidia driver (470 in my case)
- 3. Attach a monitor to dGPU and leave iGPU connect to nothing.
- (in my test environment, there is the other ethernet card and TBT4 cards)
- * Setup a cronjob,
- e.g. @reboot /home/u/test.sh
- * Have a test script in something like /home/u/test.sh as
+ * The environment:
+ 1. A desktop or workstation which containing an iGPU.
+ 2. Plug a nvidia graphic card to the system and installing proprietary
+ nvidia driver (470 in my case)
+ 3. Attach a monitor to dGPU and leave iGPU connect to nothing.
+ (in my test environment, there is the other ethernet card and TBT4 cards)
+ * Setup a cronjob,
+ e.g. @reboot /home/u/test.sh
+ * Have a test script in something like /home/u/test.sh as
#!/bin/bash
sleep 20
count="$(cat /home/u/count)"
count=$((count+1))
echo $count | tee /home/u/count
journalctl -b | grep -q -i wayland || sudo reboot
- * the system will probably stuck in black-screen or boot LOGO.
- * Before applying the fix, the fail rate is 6/24 (fail 6 time in 24 runs).
- * After applying the fix, it got pass within 90 reboot cycles.
+ * the system will probably stuck in black-screen or boot LOGO.
+ * Before applying the fix, the fail rate is 6/24 (fail 6 time in 24 runs).
+ * After applying the fix, it got pass within 90 reboot cycles.
[Where problems could occur]
- * The patch checkes device/boot_vga with tag "master-of-seat". If a system
without any GPU as boot_vga then it will fall in infinite loop.
- * I tried to detach all monitors from the system and the boot_vga still
exist (default to use iGPU, the first device found during initialization)
- * I don't think they will a case which boot_vga doesn't exist in this moment
because:
+ * The patch checkes device/boot_vga with tag "master-of-seat". If a system
without any GPU as boot_vga then it will wait 10 seconds in the loop.
+ * I tried to detach all monitors from the system and the boot_vga still
exist (default to use iGPU, the first device found during initialization)
+ * I don't think they will a case which boot_vga doesn't exist in this moment
because:
In drivers/gpu/vga/vgaarb.c (linux package)
vga_arb_select_default_device() has a fallback function to determine the
boot_vga device to prevent firmware doesn't pass correct efifb to linux-kernel.
---
Test environment/steps:
1. A desktop or workstation which containing an iGPU.
2. Plug a nvidia graphic card to the system and installing proprietary nvidia
driver (470 in my case)
3. Attach a monitor to dGPU and leave iGPU connect to nothing.
(in my test environment, there is the other ethernet card and TBT4 cards)
4. Reboot system.
Based on:
$ cat /lib/udev/rules.d/61-gdm.rules
# disable Wayland on Hi1710 chipsets
ATTR{vendor}=="0x19e5", ATTR{device}=="0x1711",
RUN+="/usr/lib/gdm3/gdm-disable-wayland"
# disable Wayland when using the proprietary nvidia driver
DRIVER=="nvidia", RUN+="/usr/lib/gdm3/gdm-disable-wayland"
It will disable wayland by default if proprietary nvidia driver load.
But in some race condition cases, the nvidia probe is later than gnome
launches. (The fail rate is 6/24.)
Thus, ubuntu-gdm has a fix for Bug#1794280 to add
"ExecStartPre=@libexecdir@/gdm-wait-for-drm".
The gdm-wait-for-drm is intend to make sure all drm udev devices
enumerated before launching gdm.
It rely on at least one "master-of-seat" graphic card for gdm but it's not
rigorous enough.
Since most of graphic cards are own "master-of-seat"[1].
In my case, it detects the iGPU is probed but dGPU.
However, the display is attached to dGPU.
We need to make sure the targeted gpu (connecting to monitor) is probe
before launching gdm.
[1] https://www.freedesktop.org/wiki/Software/systemd/multiseat/
/lib/udev/rules.d/71-seat.rules
/lib/udev/rules.d/71-nvidia.rules
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https://bugs.launchpad.net/bugs/1958488
Title:
[nvidia][xorg] display hangs on boot LOGO
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