Date:   Tue, 11 Dec 2018 06:35:20 +0000
From:   "Grumbach, Emmanuel" <emmanuel.grumbach@...el.com>
To:     Bjorn Helgaas <helgaas@...nel.org>
CC:     "bjorn@...gaas.com" <bjorn@...gaas.com>,
        "linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
        "Mertarg10@...il.com" <Mertarg10@...il.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: Fwd: [Bug 201647] New: Intel Wireless card 3165 does not get
 detected but bluetooth works

> > > >
> > > > https://bugzilla.kernel.org/show_bug.cgi?id=201647
> > > >
> > > >             Bug ID: 201647
> > > >            Summary: Intel Wireless card 3165 does not get detected but
> > > >                     bluetooth works
> > > >            Product: Drivers
> > > >            Version: 2.5
> > > >     Kernel Version: 4.19.1
> > > >           Hardware: Intel
> > > >                 OS: Linux
> > > >               Tree: Mainline
> > > >             Status: NEW
> > > >           Severity: high
> > > >           Priority: P1
> > > >          Component: PCI
> > > >           Assignee: drivers_pci@...nel-bugs.osdl.org
> > > >           Reporter: Mertarg10@...il.com
> > > >         Regression: No
> > > >
> > > > This bug affects most of the devices with a Celeron N4000 and an
> > > > Intel wifi 3165 Ac adapter.
> > > >
> > > > When using Linux wifi is not working however, Bluetooth is working
> > > > fine.  Also, Bluetooth part of this chip is connected via btusb
> > > > and the wifi part of this chip is connected via PCIe.
> > >
> > > Can you attach a screenshot of the Windows 10 device manager info
> > > for the wifi adapter to the bugzilla?  If you can get a raw hex dump
> > > of its config space, that would be awesome.
> > >
> > > Also attach a copy of your kernel .config file (typically in /boot/).
> > >
> > > My only guess is that maybe the system keeps wifi completely powered
> > > down and uses hotplug to add it when needed.  [1] mentions wifi
> > > being on pcibus 1 under Windows.  Your lspci does show bridge
> > > 00:13.0 leading to bus 01, but Linux doesn't find any devices on bus 01.
> > >
> > > Hotplug could be done via either acpiphp (ACPI mediated hotplug) or
> > > pciehp (native PCIe hotplug).  Your dmesg shows you do have acpiphp.
> > >
> > > I can't tell about pciehp (your .config will show that), but I think
> > > pciehp will only claim bridges where SltCap contains HotPlug+, and
> > > yours shows HotPlug- , so I don't think pciehp will do anything on your
> system.
> > >
> > > Even if the system does use hotplug, I don't know what mechanism the
> > > OS would use to wake up the device, since we don't know it even
> > > exists.  I guess there could be some magic switch accessible via USB.
> > > But if that were the case, I'm sure Emmanuel would know about it.
> >
> > Hm... Don't be so sure... :)
> > I don't think we have anything as fancy as this.
> > I guess you can try to dig into the BIOS settings?
> > I have heard of such a switch that would make the device disappear.
> 
> It's worth looking, but I don't understand how a BIOS switch would solve this
> problem.  I assume that with the same BIOS settings, Windows works and
> Linux fails.

I guess I had a typo there... I have *not* heard of such a switch.

> 
> Maybe there would be a clue in an acpidump from affected machines, e.g.,
> maybe we'd see some kind of ACPI hotplug notification.  That seems like a
> long shot because we do have acpiphp in the kernel, and it *should* be
> handling such notifications, but it could always be broken.
> 
> The Windows device manager info (requested above) would be interesting.
> 
Indeed.
FWIW: I saw another problem like this with a 9650 device.

PS: PCI folks don't use bugzilla's anymore? It's all over the mailing list?

Powered by blists - more mailing lists