Re: [PATCH V2] PCI/ASPM: Save/restore L1SS Capability for suspend/resume
From: Kai-Heng Feng
Date: Tue Aug 23 2022 - 12:33:20 EST
Hi Vidya,
On Tue, Aug 9, 2022 at 12:17 AM Vidya Sagar <vidyas@xxxxxxxxxx> wrote:
>
> Thanks Lukasz for the update.
> I think confirms that there is no issue with the patch as such.
> Bjorn, could you please define the next step for this patch?
I think the L1SS cap went away _after_ L1SS registers are restored,
since your patch already check the cap before doing any write:
+ aspm_l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
+ if (!aspm_l1ss)
+ return;
That means it's more likely to be caused by the following change:
+ pci_write_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL2, *cap++);
+ pci_write_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL1, *cap++);
So is it possible to clear PCI_L1SS_CTL1 before setting PCI_L1SS_CTL2,
like what aspm_calc_l1ss_info() does?
Kai-Heng
>
> Thanks,
> Vidya Sagar
>
> On 8/8/2022 7:37 PM, Lukasz Majczak wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > śr., 3 sie 2022 o 14:55 Vidya Sagar <vidyas@xxxxxxxxxx> napisał(a):
> >>
> >> Thanks Lukasz for the logs.
> >> I still that the L1SS capability in the root port (00:14.0) disappeared
> >> after resume.
> >> I still don't understand how this patch can make the capability register
> >> itself disappear. Honestly, I still see this as a HW issue.
> >> Bjorn, could you please throw some light on this?
> >>
> >> Thanks,
> >> Vidya Sagar
> >>
> >> On 8/3/2022 5:34 PM, Lukasz Majczak wrote:
> >>> External email: Use caution opening links or attachments
> >>>
> >>>
> >>> pt., 29 lip 2022 o 16:36 Vidya Sagar <vidyas@xxxxxxxxxx> napisał(a):
> >>>>
> >>>> Hi Lukasz,
> >>>> Thanks for sharing your observations.
> >>>>
> >>>> Could you please also share the output of 'sudo lspci -vvvv' before and
> >>>> after suspend-resume cycle with the latest linux-next?
> >>>> Do we still see the L1SS capabilities getting disappeared post resume?
> >>>>
> >>>> Thanks,
> >>>> Vidya Sagar
> >>>>
> >>>> On 7/29/2022 3:09 PM, Lukasz Majczak wrote:
> >>>>> External email: Use caution opening links or attachments
> >>>>>
> >>>>>
> >>>>> wt., 26 lip 2022 o 09:20 Lukasz Majczak <lma@xxxxxxxxxxxx> napisał(a):
> >>>>>>
> >>>>>> wt., 26 lip 2022 o 00:51 Rajat Jain <rajatja@xxxxxxxxxx> napisał(a):
> >>>>>>>
> >>>>>>> Hello,
> >>>>>>>
> >>>>>>> On Sat, Jul 23, 2022 at 10:03 AM Vidya Sagar <vidyas@xxxxxxxxxx> wrote:
> >>>>>>>>
> >>>>>>>> Agree with Bjorn's observations.
> >>>>>>>> The fact that the L1SS capability registers themselves disappeared in
> >>>>>>>> the root port post resume indicates that there seems to be something
> >>>>>>>> wrong with the BIOS itself.
> >>>>>>>> Could you please check from that perspective?
> >>>>>>>
> >>>>>>> ChromeOS Intel platforms use S0ix (suspend-to-idle) for suspend. This
> >>>>>>> is a shallower sleep state that preserves more state than, for e.g. S3
> >>>>>>> (suspend-to-RAM). When we use S0ix, then BIOS does not come in picture
> >>>>>>> at all. i.e. after the kernel runs its suspend routines, it just puts
> >>>>>>> the CPU into S0ix state. So I do not think there is a BIOS angle to
> >>>>>>> this.
> >>>>>>>
> >>>>>>>
> >>>>>>>>
> >>>>>>>> Thanks,
> >>>>>>>> Vidya Sagar
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On 7/22/2022 11:12 PM, Bjorn Helgaas wrote:
> >>>>>>>>> External email: Use caution opening links or attachments
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> On Fri, Jul 22, 2022 at 11:41:14AM +0200, Lukasz Majczak wrote:
> >>>>>>>>>> pt., 22 lip 2022 o 09:31 Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> napisał(a):
> >>>>>>>>>>> On Fri, Jul 15, 2022 at 6:38 PM Ben Chuang <benchuanggli@xxxxxxxxx> wrote:
> >>>>>>>>>>>> On Tue, Jul 5, 2022 at 2:00 PM Vidya Sagar <vidyas@xxxxxxxxxx> 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.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
> >>>>>>>>>>>>> Tested-by: Abhishek Sahu <abhsahu@xxxxxxxxxx>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Hi Vidya,
> >>>>>>>>>>>>
> >>>>>>>>>>>> I tested this patch on kernel v5.19-rc6.
> >>>>>>>>>>>> The test device is GL9755 card reader controller on Intel i5-10210U RVP.
> >>>>>>>>>>>> This patch can restore L1SS after suspend/resume.
> >>>>>>>>>>>>
> >>>>>>>>>>>> The test results are as follows:
> >>>>>>>>>>>>
> >>>>>>>>>>>> After Boot:
> >>>>>>>>>>>> #lspci -d 17a0:9755 -vvv | grep -A5 "L1 PM Substates"
> >>>>>>>>>>>> Capabilities: [110 v1] L1 PM Substates
> >>>>>>>>>>>> L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+
> >>>>>>>>>>>> ASPM_L1.1+ L1_PM_Substates+
> >>>>>>>>>>>> PortCommonModeRestoreTime=255us
> >>>>>>>>>>>> PortTPowerOnTime=3100us
> >>>>>>>>>>>> L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
> >>>>>>>>>>>> T_CommonMode=0us LTR1.2_Threshold=3145728ns
> >>>>>>>>>>>> L1SubCtl2: T_PwrOn=3100us
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> After suspend/resume without this patch.
> >>>>>>>>>>>> #lspci -d 17a0:9755 -vvv | grep -A5 "L1 PM Substates"
> >>>>>>>>>>>> Capabilities: [110 v1] L1 PM Substates
> >>>>>>>>>>>> L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+
> >>>>>>>>>>>> ASPM_L1.1+ L1_PM_Substates+
> >>>>>>>>>>>> PortCommonModeRestoreTime=255us
> >>>>>>>>>>>> PortTPowerOnTime=3100us
> >>>>>>>>>>>> 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.
> >>>>>>>>>>>> #lspci -d 17a0:9755 -vvv | grep -A5 "L1 PM Substates"
> >>>>>>>>>>>> Capabilities: [110 v1] L1 PM Substates
> >>>>>>>>>>>> L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+
> >>>>>>>>>>>> ASPM_L1.1+ L1_PM_Substates+
> >>>>>>>>>>>> PortCommonModeRestoreTime=255us
> >>>>>>>>>>>> PortTPowerOnTime=3100us
> >>>>>>>>>>>> L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
> >>>>>>>>>>>> T_CommonMode=0us LTR1.2_Threshold=3145728ns
> >>>>>>>>>>>> L1SubCtl2: T_PwrOn=3100us
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Tested-by: Ben Chuang <benchuanggli@xxxxxxxxx>
> >>>>>>>>>>>
> >>>>>>>>>>> Forgot to add mine:
> >>>>>>>>>>> Tested-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> >>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>> Best regards,
> >>>>>>>>>>>> Ben Chuang
> >>>>>>>>>>>>
> >>>>>>>>>>>>
> >>>>>>>>>>>>> ---
> >>>>>>>>>>>>> Hi,
> >>>>>>>>>>>>> Kenneth R. Crudup <kenny@xxxxxxxxx>, Could you please verify this patch
> >>>>>>>>>>>>> on your laptop (Dell XPS 13) one last time?
> >>>>>>>>>>>>> IMHO, the regression observed on your laptop with an old version of the patch
> >>>>>>>>>>>>> could be due to a buggy old version BIOS in the laptop.
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> Thanks,
> >>>>>>>>>>>>> Vidya Sagar
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> drivers/pci/pci.c | 7 +++++++
> >>>>>>>>>>>>> drivers/pci/pci.h | 4 ++++
> >>>>>>>>>>>>> drivers/pci/pcie/aspm.c | 44 +++++++++++++++++++++++++++++++++++++++++
> >>>>>>>>>>>>> 3 files changed, 55 insertions(+)
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> >>>>>>>>>>>>> index cfaf40a540a8..aca05880aaa3 100644
> >>>>>>>>>>>>> --- a/drivers/pci/pci.c
> >>>>>>>>>>>>> +++ b/drivers/pci/pci.c
> >>>>>>>>>>>>> @@ -1667,6 +1667,7 @@ int pci_save_state(struct pci_dev *dev)
> >>>>>>>>>>>>> return i;
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> pci_save_ltr_state(dev);
> >>>>>>>>>>>>> + pci_save_aspm_l1ss_state(dev);
> >>>>>>>>>>>>> pci_save_dpc_state(dev);
> >>>>>>>>>>>>> pci_save_aer_state(dev);
> >>>>>>>>>>>>> pci_save_ptm_state(dev);
> >>>>>>>>>>>>> @@ -1773,6 +1774,7 @@ void pci_restore_state(struct pci_dev *dev)
> >>>>>>>>>>>>> * LTR itself (in the PCIe capability).
> >>>>>>>>>>>>> */
> >>>>>>>>>>>>> pci_restore_ltr_state(dev);
> >>>>>>>>>>>>> + pci_restore_aspm_l1ss_state(dev);
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> pci_restore_pcie_state(dev);
> >>>>>>>>>>>>> pci_restore_pasid_state(dev);
> >>>>>>>>>>>>> @@ -3489,6 +3491,11 @@ void pci_allocate_cap_save_buffers(struct pci_dev *dev)
> >>>>>>>>>>>>> if (error)
> >>>>>>>>>>>>> pci_err(dev, "unable to allocate suspend buffer for LTR\n");
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> + error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_L1SS,
> >>>>>>>>>>>>> + 2 * sizeof(u32));
> >>>>>>>>>>>>> + if (error)
> >>>>>>>>>>>>> + pci_err(dev, "unable to allocate suspend buffer for ASPM-L1SS\n");
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> pci_allocate_vc_save_buffers(dev);
> >>>>>>>>>>>>> }
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> >>>>>>>>>>>>> index e10cdec6c56e..92d8c92662a4 100644
> >>>>>>>>>>>>> --- a/drivers/pci/pci.h
> >>>>>>>>>>>>> +++ b/drivers/pci/pci.h
> >>>>>>>>>>>>> @@ -562,11 +562,15 @@ void pcie_aspm_init_link_state(struct pci_dev *pdev);
> >>>>>>>>>>>>> void pcie_aspm_exit_link_state(struct pci_dev *pdev);
> >>>>>>>>>>>>> void pcie_aspm_pm_state_change(struct pci_dev *pdev);
> >>>>>>>>>>>>> void pcie_aspm_powersave_config_link(struct pci_dev *pdev);
> >>>>>>>>>>>>> +void pci_save_aspm_l1ss_state(struct pci_dev *dev);
> >>>>>>>>>>>>> +void pci_restore_aspm_l1ss_state(struct pci_dev *dev);
> >>>>>>>>>>>>> #else
> >>>>>>>>>>>>> static inline void pcie_aspm_init_link_state(struct pci_dev *pdev) { }
> >>>>>>>>>>>>> static inline void pcie_aspm_exit_link_state(struct pci_dev *pdev) { }
> >>>>>>>>>>>>> static inline void pcie_aspm_pm_state_change(struct pci_dev *pdev) { }
> >>>>>>>>>>>>> static inline void pcie_aspm_powersave_config_link(struct pci_dev *pdev) { }
> >>>>>>>>>>>>> +static inline void pci_save_aspm_l1ss_state(struct pci_dev *dev) { }
> >>>>>>>>>>>>> +static inline void pci_restore_aspm_l1ss_state(struct pci_dev *dev) { }
> >>>>>>>>>>>>> #endif
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> #ifdef CONFIG_PCIE_ECRC
> >>>>>>>>>>>>> diff --git a/drivers/pci/pcie/aspm.c b/drivers/pci/pcie/aspm.c
> >>>>>>>>>>>>> index a96b7424c9bc..2c29fdd20059 100644
> >>>>>>>>>>>>> --- a/drivers/pci/pcie/aspm.c
> >>>>>>>>>>>>> +++ b/drivers/pci/pcie/aspm.c
> >>>>>>>>>>>>> @@ -726,6 +726,50 @@ static void pcie_config_aspm_l1ss(struct pcie_link_state *link, u32 state)
> >>>>>>>>>>>>> PCI_L1SS_CTL1_L1SS_MASK, val);
> >>>>>>>>>>>>> }
> >>>>>>>>>>>>>
> >>>>>>>>>>>>> +void pci_save_aspm_l1ss_state(struct pci_dev *dev)
> >>>>>>>>>>>>> +{
> >>>>>>>>>>>>> + int aspm_l1ss;
> >>>>>>>>>>>>> + struct pci_cap_saved_state *save_state;
> >>>>>>>>>>>>> + u32 *cap;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + if (!pci_is_pcie(dev))
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + aspm_l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
> >>>>>>>>>>>>> + if (!aspm_l1ss)
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS);
> >>>>>>>>>>>>> + if (!save_state)
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + cap = (u32 *)&save_state->cap.data[0];
> >>>>>>>>>>>>> + pci_read_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL2, cap++);
> >>>>>>>>>>>>> + pci_read_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL1, cap++);
> >>>>>>>>>>>>> +}
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> +void pci_restore_aspm_l1ss_state(struct pci_dev *dev)
> >>>>>>>>>>>>> +{
> >>>>>>>>>>>>> + int aspm_l1ss;
> >>>>>>>>>>>>> + struct pci_cap_saved_state *save_state;
> >>>>>>>>>>>>> + u32 *cap;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + if (!pci_is_pcie(dev))
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + aspm_l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS);
> >>>>>>>>>>>>> + if (!aspm_l1ss)
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_L1SS);
> >>>>>>>>>>>>> + if (!save_state)
> >>>>>>>>>>>>> + return;
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> + cap = (u32 *)&save_state->cap.data[0];
> >>>>>>>>>>>>> + pci_write_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL2, *cap++);
> >>>>>>>>>>>>> + pci_write_config_dword(dev, aspm_l1ss + PCI_L1SS_CTL1, *cap++);
> >>>>>>>>>>>>> +}
> >>>>>>>>>>>>> +
> >>>>>>>>>>>>> static void pcie_config_aspm_dev(struct pci_dev *pdev, u32 val)
> >>>>>>>>>>>>> {
> >>>>>>>>>>>>> pcie_capability_clear_and_set_word(pdev, PCI_EXP_LNKCTL,
> >>>>>>>>>>>>> --
> >>>>>>>>>>>>> 2.17.1
> >>>>>>>>>>>>>
> >>>>>>>>>>
> >>>>>>>>>> Hi,
> >>>>>>>>>>
> >>>>>>>>>> With this patch (and also mentioned
> >>>>>>>>>> https://lore.kernel.org/all/20220509073639.2048236-1-kai.heng.feng@xxxxxxxxxxxxx/)
> >>>>>>>>>> applied on 5.10 (chromeos-5.10) I am observing problems after
> >>>>>>>>>> suspend/resume with my WiFi card - it looks like whole communication
> >>>>>>>>>> via PCI fails. Attaching logs (dmesg, lspci -vvv before suspend/resume
> >>>>>>>>>> and after) https://gist.github.com/semihalf-majczak-lukasz/fb36dfa2eff22911109dfb91ab0fc0e3
> >>>>>>>>>>
> >>>>>>>>>> I played a little bit with this code and it looks like the
> >>>>>>>>>> pci_write_config_dword() to the PCI_L1SS_CTL1 breaks it (don't know
> >>>>>>>>>> why, not a PCI expert).
> >>>>>>>>>
> >>>>>>>>> Thanks a lot for testing this! I'm not quite sure what to make of the
> >>>>>>>>> results since v5.10 is fairly old (Dec 2020) and I don't know what
> >>>>>>>>> other changes are in chromeos-5.10.
> >>>>>>>
> >>>>>>> Lukasz: I assume you are running this on Atlas and are seeing this bug
> >>>>>>> when uprev'ving it to 5.10 kernel. Can you please try it on a newer
> >>>>>>> Intel platform that have the latest upstream kernel running already
> >>>>>>> and see if this can be reproduced there too?
> >>>>>>> Note that the wifi PCI device is different on newer Intel platforms,
> >>>>>>> but platform design is similar enough that I suspect we should see
> >>>>>>> similar bug on those too. The other option is to try the latest
> >>>>>>> ustream kernel on Atlas. Perhaps if we just care about wifi (and
> >>>>>>> ignore bringing up the graphics stack and GUI), it may come up
> >>>>>>> sufficiently enough to try this patch?
> >>>>>>>
> >>>>>>> Thanks,
> >>>>>>>
> >>>>>>> Rajat
> >>>>>>>
> >>>>>>>
> >>>>>>>>>
> >>>>>>>>> Random observations, no analysis below. This from your dmesg
> >>>>>>>>> certainly looks like PCI reads failing and returning ~0:
> >>>>>>>>>
> >>>>>>>>> Timeout waiting for hardware access (CSR_GP_CNTRL 0xffffffff)
> >>>>>>>>> iwlwifi 0000:01:00.0: 00000000: ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff ffffffff
> >>>>>>>>> iwlwifi 0000:01:00.0: Device gone - attempting removal
> >>>>>>>>> Hardware became unavailable upon resume. This could be a software issue prior to suspend or a hardware issue.
> >>>>>>>>>
> >>>>>>>>> And then we re-enumerate 01:00.0 and it looks like it may have been
> >>>>>>>>> reset (BAR is 0):
> >>>>>>>>>
> >>>>>>>>> pci 0000:01:00.0: [8086:095a] type 00 class 0x028000
> >>>>>>>>> pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x00001fff 64bit]
> >>>>>>>>>
> >>>>>>>>> lspci diffs from before/after suspend:
> >>>>>>>>>
> >>>>>>>>> 00:14.0 PCI bridge: Intel Corporation Celeron N3350/Pentium N4200/Atom E3900 Series PCI Express Port B #1 (rev fb) (prog-if 00 [Normal decode])
> >>>>>>>>> Bus: primary=00, secondary=01, subordinate=01, sec-latency=64
> >>>>>>>>> - DevSta: CorrErr- NonFatalErr+ FatalErr- UnsupReq+ AuxPwr+ TransPend-
> >>>>>>>>> + DevSta: CorrErr+ NonFatalErr- FatalErr- UnsupReq- AuxPwr+ TransPend-
> >>>>>>>>> - LnkCtl: ASPM L1 Enabled; RCB 64 bytes, Disabled- CommClk+
> >>>>>>>>> + LnkCtl: ASPM Disabled; RCB 64 bytes, Disabled- CommClk+
> >>>>>>>>> - LnkSta2: Current De-emphasis Level: -6dB, EqualizationComplete- EqualizationPhase1-
> >>>>>>>>> + LnkSta2: Current De-emphasis Level: -3.5dB, EqualizationComplete- EqualizationPhase1-
> >>>>>>>>> - Capabilities: [150 v0] Null
> >>>>>>>>> - Capabilities: [200 v1] L1 PM Substates
> >>>>>>>>> - L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+ L1_PM_Substates+
> >>>>>>>>> - PortCommonModeRestoreTime=40us PortTPowerOnTime=10us
> >>>>>>>>> - L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
> >>>>>>>>> - T_CommonMode=40us LTR1.2_Threshold=98304ns
> >>>>>>>>> - L1SubCtl2: T_PwrOn=60us
> >>>>>>>>>
> >>>>>>>>> The DevSta differences might be BIOS bugs, probably not relevant.
> >>>>>>>>> Interesting that ASPM is disabled, maybe didn't get enabled after
> >>>>>>>>> re-enumerating 01:00.0? Strange that the L1 PM Substates capability
> >>>>>>>>> disappeared.
> >>>>>>>>>
> >>>>>>>>> 01:00.0 Network controller: Intel Corporation Wireless 7265 (rev 59)
> >>>>>>>>> LnkCtl: ASPM L1 Enabled; RCB 64 bytes, Disabled- CommClk+
> >>>>>>>>> - ExtSynch- ClockPM+ AutWidDis- BWInt- AutBWInt-
> >>>>>>>>> + ExtSynch- ClockPM- AutWidDis- BWInt- AutBWInt-
> >>>>>>>>> Capabilities: [154 v1] L1 PM Substates
> >>>>>>>>> L1SubCap: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+ L1_PM_Substates+
> >>>>>>>>> PortCommonModeRestoreTime=30us PortTPowerOnTime=60us
> >>>>>>>>> - L1SubCtl1: PCI-PM_L1.2+ PCI-PM_L1.1+ ASPM_L1.2+ ASPM_L1.1+
> >>>>>>>>> - T_CommonMode=0us LTR1.2_Threshold=98304ns
> >>>>>>>>> + L1SubCtl1: PCI-PM_L1.2- PCI-PM_L1.1- ASPM_L1.2- ASPM_L1.1-
> >>>>>>>>> + T_CommonMode=0us LTR1.2_Threshold=0ns
> >>>>>>>>>
> >>>>>>>>> Dmesg claimed we reconfigured common clock config. Maybe ASPM didn't
> >>>>>>>>> get reinitialized after re-enumeration? Looks like we didn't restore
> >>>>>>>>> L1SubCtl1.
> >>>>>>>>>
> >>>>>>>>> Bjorn
> >>>>>>>>>
> >>>>>>
> >>>>>> Hi,
> >>>>>>
> >>>>>> Thank you all for the response and input! As Rajat mentioned I'm using
> >>>>>> chromebook - but not Atlas (Amberlake) - in this case it is Babymega
> >>>>>> (Apollolake) - I will try to load most recent kernel and give it a
> >>>>>> try once again.
> >>>>>>
> >>>>>> Best regards,
> >>>>>> Lukasz
> >>>>>
> >>>>> Hi,
> >>>>>
> >>>>> I have applied this patch on top of v5.19-rc7 (chromeos) and I'm
> >>>>> still getting same results:
> >>>>> https://gist.github.com/semihalf-majczak-lukasz/4b716704c21a3758d6711b2030ea34b9
> >>>>>
> >>>>> Best regards,
> >>>>> Lukasz
> >>>>>
> >>> Hi Vidya,
> >>>
> >>> Sorry for the long delay, I have retested your patch on top of
> >>> linux-next/master (next-20220802) - the results for my device remain
> >>> the same.
> >>> Here are the logs (lspci -vvv before suspend, lspci -vvv after resume and dmesg)
> >>> https://gist.github.com/semihalf-majczak-lukasz/c7bfd811359f23278034056a8002b3ef
> >>> Let me know if you need any more logs and/or tests.
> >>>
> >>> Best regards,
> >>> Lukasz
> >>>
> > Hi Vidya,
> >
> > After your last email, I've re-tested my setup and (without your
> > patch) the capability register also disappears - so it looks there is
> > - in fact - some problem in my setup and your patch just brings it to
> > the top as after resume tries to write to a register that is no longer
> > present. I'm very sorry for the confusion here and I've not notice
> > that at the very beginning.
> >
> > Best regards,
> > Lukasz
> >