Re: [BISECTED] tpm CLKRUN breaks PS/2 keyboard and touchpad on Braswell system

From: Jarkko Sakkinen
Date: Tue Dec 19 2017 - 08:04:45 EST


On Mon, Dec 18, 2017 at 01:19:02PM -0700, Jason Gunthorpe wrote:
> On Mon, Dec 18, 2017 at 07:34:29PM +0000, Shaikh, Azhar wrote:
>
> > >IIUC, if CLKRUN_EN is enabled, then all the devices attached to the
> > >LPC bus have to support the CLKRUN protocol. My guess is that on
> > >some Braswell systems LPC power management is enabled but the TPM
> > >device doesn't have CLKRUN support.
> >
> > I think this is what might be happening here.
>
> That makes it a BIOS bug, not a chipset bug, and we shouldn't be
> trying to fix it like this in Linux.
>
> Based on the original discussion I always thought this was an Intel
> chipset bug and applies to all cases.
>
> Jason

It would not be first time when some BIOS issues are circumvented in the
kernel.

/Jarkko