RE: [PATCH] x86/gpu: add JSL stolen memory support

["Surendrakumar Upadhyay, TejaskumarX" <tejaskumarx.surendrakumar.upadhyay@intel.com>]

Hello,

Have we decided anything on this patch?

Thanks,
Tejas

> -----Original Message-----
> From: Surendrakumar Upadhyay, TejaskumarX
> Sent: 03 December 2020 21:40
> To: Bjorn Helgaas <helgaas@kernel.org>; Joonas Lahtinen
> <joonas.lahtinen@linux.intel.com>
> Cc: Jesse Barnes <jsbarnes@google.com>; Daniel Vetter <daniel@ffwll.ch>;
> Linux PCI <linux-pci@vger.kernel.org>; Linux Kernel Mailing List <linux-
> kernel@vger.kernel.org>; X86 ML <x86@kernel.org>; Borislav Petkov
> <bp@alien8.de>; De Marchi, Lucas <lucas.demarchi@intel.com>; Roper,
> Matthew D <matthew.d.roper@intel.com>; Pandey, Hariom
> <hariom.pandey@intel.com>; Jani Nikula <jani.nikula@linux.intel.com>; Vivi,
> Rodrigo <rodrigo.vivi@intel.com>; David Airlie <airlied@linux.ie>
> Subject: RE: [PATCH] x86/gpu: add JSL stolen memory support
> 
> Okay then I will wait for someone to respond with "Reviewed-by". So this can
> be merged.
> 
> Thanks,
> Tejas
> 
> > -----Original Message-----
> > From: Bjorn Helgaas <helgaas@kernel.org>
> > Sent: 03 December 2020 20:55
> > To: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
> > Cc: Surendrakumar Upadhyay, TejaskumarX
> > <tejaskumarx.surendrakumar.upadhyay@intel.com>; Jesse Barnes
> > <jsbarnes@google.com>; Daniel Vetter <daniel@ffwll.ch>; Linux PCI
> > <linux- pci@vger.kernel.org>; Linux Kernel Mailing List <linux-
> > kernel@vger.kernel.org>; X86 ML <x86@kernel.org>; Borislav Petkov
> > <bp@alien8.de>; De Marchi, Lucas <lucas.demarchi@intel.com>; Roper,
> > Matthew D <matthew.d.roper@intel.com>; Pandey, Hariom
> > <hariom.pandey@intel.com>; Jani Nikula <jani.nikula@linux.intel.com>;
> > Vivi, Rodrigo <rodrigo.vivi@intel.com>; David Airlie
> > <airlied@linux.ie>
> > Subject: Re: [PATCH] x86/gpu: add JSL stolen memory support
> >
> > On Thu, Dec 03, 2020 at 10:46:29AM +0200, Joonas Lahtinen wrote:
> > > Quoting Bjorn Helgaas (2020-12-02 22:22:53)
> > > > On Wed, Dec 02, 2020 at 05:21:58AM +0000, Surendrakumar Upadhyay,
> > TejaskumarX wrote:
> > > > > Yes it fails all the tests which are allocating from this stolen
> > > > > memory bunch. For example IGT tests like "
> > > > > igt@kms_frontbuffer_tracking@-[fbc|fbcpsr].* |
> > > > > igt@kms_fbcon_fbt@fbc.* " are failing as they totally depend to
> > > > > work on stolen memory.
> > >
> > > That's just because we have de-duped the stolen memory detection code.
> > > If it's not detected at the early quirks, it's not detected by the
> > > driver at all.
> > >
> > > So if the patch is not merged to early quirks, we'd have to refactor
> > > the code to add alternative detection path to i915. Before that is
> > > done, the failures are expected.
> > >
> > > > I'm sure that means something to graphics developers, but I have
> > > > no idea!  Do you have URLs for the test case source, outputs,
> > > > dmesg log, lspci info, bug reports, etc?
> > >
> > > The thing is, the bug reports for stuff like this would only start
> > > to flow after Jasperlake systems are shipping widely and the less
> > > common OEMs start integrating it to into strangely behaving BIOSes.
> > > Or that is the assumption.
> > >
> > > If it's fine to merge this through i915 for now with an Acked-by,
> > > like the previous patches, that'd be great. We can start a
> > > discussion on if the new platforms are affected anymore. But I'd
> > > rather not drop it before we have that understanding, as the
> > > previous problems have included boot time memory corruption.
> > >
> > > Would that work?
> >
> > Like I said, I'm not objecting if somebody else wants to apply this.
> >
> > I'm just pointing out that there's a little bit of voodoo here because
> > it's not clear what makes a BIOS strangely behaving or what causes
> > boot-time memory corruption, and that means we don't really have any
> > hope of resolving this stream of quirk updates.
> >
> > Bjorn