APPLIED Re: [PATCH 0/1] [SRU][OEM-5.10] Add an _OSI string for the BIOS to

[Timo Aaltonen]

On 21.5.2021 10.49, chris.chiu at canonical.com wrote:
> From: Chris Chiu <chris.chiu at canonical.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1929166
> 
> [Impact]
> The NVIDIA GPU will fall off the bus after exiting s2idle in TGL-H systems if the docking station with external display connected is unplugged when the system is still in s2idle. The system will be hold by the infinite loop in ACPI method IPCS and then the PCIe root port of NVIDIA gpu fails the power transition from D3cold to D0. Then display managed by the NVDIA GPU shows nothing until system reboot. Note that it only happens when NVIDIA GPU in either Performance mode or On-Demand mode.
> 
> [Fix]
> A BIOS workaround is used to skip the ACPI method PGSC which invokes IPCS to do source clock control of the PCIe root port with an _OSI string "Linux-Dell-USB4-NVWakeup". Should be removed until we get a generic fix for it.
> 
> [Test Case]
> 1. On all TigerLake-H and later platforms with NVIDIA GPU, make sure the NVIDIA GPU is running in either On-Demand mode or Performance mode.
> 2. Connect the docking station with the external display connected.
> 3. Suspend the system.
> 4. Remove the docking station when the system is suspended.
> 5. Press power button to wake up the system and wait > 1 minutes to make sure if the display comes back.
> 
> [Regression Potential]
> Low. This only works on platforms supporting "Linux-Dell-USB4-NVWakeup".
> No other platforms will be affected.
> 
> Chris Chiu (1):
>    UBUNTU: SAUCE: ACPI: avoid NVIDIA GPU fallen with an _OSI string
> 
>   drivers/acpi/osi.c | 7 +++++++
>   1 file changed, 7 insertions(+)
> 


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