* Re: [Bug] Driver mt7921e cause computer reboot.
2021-12-27 11:30 ` [Bug] Driver mt7921e cause computer reboot Mikhail Gavrilov
@ 2021-12-30 0:21 ` Bjorn Helgaas
0 siblings, 0 replies; 2+ messages in thread
From: Bjorn Helgaas @ 2021-12-30 0:21 UTC (permalink / raw)
To: Mikhail Gavrilov
Cc: Íñigo Huguet, Linux List Kernel Mailing, sean.wang,
Linux List Kernel Mailing, objelf, lorenzo, Soul.Huang,
Felix Fietkau, linux-pci, Lorenzo Bianconi, Ryder Lee
[+cc Lorenzo, Ryder (the rest of the mt7921 maintainers)]
Thread: https://lore.kernel.org/all/CABXGCsODP8ze_mvzfJKcRYxuS-esVgHXAvDXS5KN3xFUN6bWgA@mail.gmail.com/T/#u
On Mon, Dec 27, 2021 at 04:30:11PM +0500, Mikhail Gavrilov wrote:
> On Mon, 27 Dec 2021 at 15:11, Íñigo Huguet <ihuguet@redhat.com> wrote:
> > I've been experiencing similar problems, but they're solved at v5.15
> > version, at least for me.
> >
> > How are you installing the kernel? Custom build? Have you updated the
> > firmware to latest versions, as well?
>
> I use Fedora Rawhide with default kernel and firmware packages.
>
> $ uname -r
> 5.16.0-0.rc6.20211223gitbc491fb12513.44.fc36.x86_64
> $ rpm -q linux-firmware
> linux-firmware-20211027-126.fc36.noarch
>
> >
> > For me, these differences seem to be the normal effect of the driver
> > not recognizing the device.
>
> By the kernel logs, it looks like this:
> After reboot:
> $ dmesg | grep mt7921e
> [ 8.629358] mt7921e 0000:05:00.0: enabling device (0000 -> 0002)
> [ 8.630229] mt7921e 0000:05:00.0: ASIC revision: 79610010
> [ 9.687652] mt7921e: probe of 0000:05:00.0 failed with error -110
>
> # rmmod mt7921e
> # modprobe mt7921e
>
> [ 215.514503] mt7921e 0000:05:00.0: ASIC revision: feed0000
> [ 216.604741] mt7921e: probe of 0000:05:00.0 failed with error -110
>
> After cold boot after shutdown:
> $ dmesg | grep mt7921e
> [ 8.545171] mt7921e 0000:05:00.0: enabling device (0000 -> 0002)
> [ 8.545757] mt7921e 0000:05:00.0: ASIC revision: 79610010
> [ 8.631156] mt7921e 0000:05:00.0: HW/SW Version: 0x8a108a10, Build
> Time: 20211014150838a
> [ 8.912687] mt7921e 0000:05:00.0: WM Firmware Version: ____010000,
> Build Time: 20211014150922
> [ 8.938756] mt7921e 0000:05:00.0: Firmware init done
> [ 9.753257] mt7921e 0000:05:00.0 wlp5s0: renamed from wlan0
>
> It looks like something is not re-initialized after a reboot.
> Laptop BIOS is latest: Version 316
> https://dlcdnets.asus.com/pub/ASUS/GamingNB/G513QY/G513QYAS316.zip
>
> Maybe anyone from the pci mailing list can lid some light why pci
> device not re-initialized after a reboot?
Sorry for the inconvenience and thank you very much for the report!
If I understand correctly, when you do a cold boot, the mt7921e device
works properly.
But when you simply reboot, without a power off, the device does not
work, and the dmesg log contains:
pci 0000:05:00.0: [14c3:7961] type 00 class 0x028000
pci 0000:05:00.0: reg 0x10: [mem 0xfc30300000-0xfc303fffff 64bit pref]
pci 0000:05:00.0: reg 0x18: [mem 0xfc30400000-0xfc30403fff 64bit pref]
pci 0000:05:00.0: reg 0x20: [mem 0xfc30404000-0xfc30404fff 64bit pref]
...
mt7921e 0000:05:00.0: enabling device (0000 -> 0002)
mt7921e 0000:05:00.0: ASIC revision: 79610010
mt7921e: probe of 0000:05:00.0 failed with error -110
That means the device responds to PCI config reads and writes, but the
probe failed with -ETIMEDOUT after printing the ASIC revision [1].
devm_request_irq() should not return -ETIMEDOUT, but it looks like
mt7921_dma_init() can (via mt7921_dma_disable()). Maybe the mt7921e
driver can't tolerate some state the device was left in by reboot?
I don't see anything obviously wrong from a PCI core perspective. The
PCI core does not reset devices either when going down for a reboot or
when coming up at boot-time.
Bjorn
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/wireless/mediatek/mt76/mt7921/pci.c?id=v5.16-rc6#n187
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