On 8/26/2022 6:25 PM, Vidya Sagar wrote:
> Previously ASPM L1 Substates control registers (CTL1 and CTL2) weren't
> saved and restored during suspend/resume leading to L1 Substates
> configuration being lost post-resume.
>
> Save the L1 Substates control registers so that the configuration is
> retained post-resume.
>
Tested-by: Abhishek Sahu <abhsahu@xxxxxxxxxx>
> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> ---
> V3:
> * Disabled L1.2 enable fields while restoring Control-1 register
>
Thanks Vidya.
I have applied your v3 patch in 6.0-rc3 kernel and tested again.
I did 100 cycles of suspend/resume in a Alder lake based notebook
which has NVIDIA discrete GPU and it is working fine.
# lspci -d "0x10de:" -vvv|grep "L1SubCtl" -A 2
After Boot:
L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
T_CommonMode=0us LTR1.2_Threshold=753664ns
L1SubCtl2: T_PwrOn=500us
After Suspend/resume without this patch:
L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
T_CommonMode=0us LTR1.2_Threshold=0ns
L1SubCtl2: T_PwrOn=10us
After Suspend/resume with this patch:
L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
T_CommonMode=0us LTR1.2_Threshold=753664ns
L1SubCtl2: T_PwrOn=500us
So with this patch, the L1SubCtl1 and L1SubCtl2 settings are being
restored back correctly.
Regards,
Abhishek
