Re: [Bug 219755] New: Wifi card intel 7265D not detected with kernel 6.14-rc1

[Bjorn Helgaas <helgaas@kernel.org>]

For completeness, sending this to the list since most people don't
look at bugzilla.  I *think* this should be fixed by Ilpo's patch:
https://lore.kernel.org/r/20250131152913.2507-1-ilpo.jarvinen@linux.intel.com,
which I just asked Linus to pull for v6.14-rc2.

(Jian-Hong, my abject apologies because I think this whole mess was my
fault for editing your patch before applying it.  I also meant to cc
you on the pull request but obviously forgot.)

On Thu, Feb 06, 2025 at 06:47:21PM +0000, bugzilla-daemon@kernel.org wrote:
> https://bugzilla.kernel.org/show_bug.cgi?id=219755
> 
> Created attachment 307580
>   --> https://bugzilla.kernel.org/attachment.cgi?id=307580&action=edit
> Dmesg from kernel 6.14-rc1
> 
> Hi
> 
> With kernel 6.14-rc1 my wifi card is not detected anymore on my Asus UX305FA
> after boot.
> 
> Boot dmesg 6.14-rc1:
> 
> dmesg | grep iwl
> [    4.006347] iwlwifi 0000:02:00.0: Unable to change power state from D3cold
> to D0, device inaccessible
> [    4.008072] iwlwifi 0000:02:00.0: HW_REV=0xFFFFFFFF, PCI issues?
> [    4.009912] iwlwifi 0000:02:00.0: probe with driver iwlwifi failed with
> error -5
> ...

> I start bisecting and the first bad commit is:
> 
> 1db806ec06b7c6e08e8af57088da067963ddf117 is the first bad commit
> commit 1db806ec06b7c6e08e8af57088da067963ddf117
> Author: Jian-Hong Pan <jhp@endlessos.org>
> Date:   Fri Nov 15 15:22:02 2024 +0800
> 
>     PCI/ASPM: Save parent L1SS config in pci_save_aspm_l1ss_state()
> 
>     After 17423360a27a ("PCI/ASPM: Save L1 PM Substates Capability for
>     suspend/resume"), pci_save_aspm_l1ss_state(dev) saves the L1SS state for
>     "dev", and pci_restore_aspm_l1ss_state(dev) restores the state for both
>     "dev" and its parent.
> 
>     The problem is that unless pci_save_state() has been used in some other
>     path and has already saved the parent L1SS state, we will restore junk to
>     the parent, which means the L1 Substates likely won't work correctly.
> 
>     Save the L1SS config for both the device and its parent in
>     pci_save_aspm_l1ss_state().  When restoring, we need both because L1SS must
>     be enabled at the parent (the Downstream Port) before being enabled at the
>     child (the Upstream Port).
> 
>     Link: https://lore.kernel.org/r/20241115072200.37509-3-jhp@endlessos.org
>     Fixes: 17423360a27a ("PCI/ASPM: Save L1 PM Substates Capability for
> suspend/resume")
>     Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218394
>     Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
>     Signed-off-by: Jian-Hong Pan <jhp@endlessos.org>
>     [bhelgaas: parallel save/restore structure, simplify commit log, patch at
>     https://lore.kernel.org/r/20241212230340.GA3267194@bhelgaas]
>     Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
>     Tested-by: Jian-Hong Pan <jhp@endlessos.org> # Asus B1400CEAE
> 
>  drivers/pci/pcie/aspm.c | 33 ++++++++++++++++++++++++++++-----
>  1 file changed, 28 insertions(+), 5 deletions(-)
> 
> Reverting the patch and rebuild the 6.14-rc1 kernel fixed the problem for me,
> my wifi card is detected again.