Re: [REGRESSION] 2017 Pixelbook backlight control do esn’t work with 7.1 kernel

I tried reverting commit b3793af3277f65d256d67f9949e760b434ff66dd on
top of v7.1, but the resulting kernel completely hangs at 'Loading
initial ramdisk'. Even when adding 'nomodeset' via GRUB, the crash
happens so early that no kernel text or console output is ever
printed. It appears this Intel THC merge cannot be cleanly isolated or
reverted on v7.1 without causing an immediate early boot failure on
this hardware.

Papool S. Chaudhari
PRA Law
14011 Pebble Hills Blvd. Ste 105
PMB #1003
El Paso, Texas 79938
(214) 702-1150
[email protected]


On Fri, Jul 10, 2026 at 11:32 PM Greg KH <[email protected]> wrote:
>
> On Fri, Jul 10, 2026 at 11:09:34PM -0600, Papool Chaudhari wrote:
> > Greg,
> >
> > I did git bisect and this is the offending commit:
> >
> > b3793af3277f65d256d67f9949e760b434ff66dd is the first 'bad' commit
> > commit b3793af3277f65d256d67f9949e760b434ff66dd
> > Merge: 51cc1c427461 88919bedabb8
> > Author: Jiri Kosina <[email protected]>
> > Date: Thu Apr 16 21:08:14 2026 +0200
> >
> >    Merge branch 'for-7.1/intel-thc' into for-linus
> >
> >    - power management improvements to intel-thc-hid driver (Even Xu)
> >
> > drivers/hid/intel-thc-hid/intel-quickspi/pci-quickspi.c | 16
> > ++++++++++------
> > drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.c | 47
> > +++++++++++++++++++++++++++++++++++++++++++++++
> > drivers/hid/intel-thc-hid/intel-thc/intel-thc-hw.h | 4 ++++
> > 3 files changed, 61 insertions(+), 6 deletions(-)
>
> Odd that a merge commit is the issue.  ANd if you revert that change,
> all is good?
>
> thanks,
>
> greg k-h