[PATCH 1/2] drm/amdgpu: Move HDP remapping earlier during init

[Alex Deucher]

On Thu, Sep 8, 2022 at 10:08 AM Deucher, Alexander
<Alexander.Deucher at amd.com> wrote:
>
> [Public]
>
> > -----Original Message-----
> > From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
> > Bjorn Helgaas
> > Sent: Thursday, August 25, 2022 2:02 PM
> > To: Lazar, Lijo <Lijo.Lazar at amd.com>
> > Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>; Kuehling, Felix
> > <Felix.Kuehling at amd.com>; amd-gfx at lists.freedesktop.org;
> > tseewald at gmail.com; Deucher, Alexander
> > <Alexander.Deucher at amd.com>; sr at denx.de; Koenig, Christian
> > <Christian.Koenig at amd.com>; Zhang, Hawking <Hawking.Zhang at amd.com>
> > Subject: Re: [PATCH 1/2] drm/amdgpu: Move HDP remapping earlier during
> > init
> >
> > [+cc Greg, no action needed yet, just FYI that stable will want these]
> >
> > On Thu, Aug 25, 2022 at 02:28:19PM +0530, Lijo Lazar wrote:
> > > HDP flush is used early in the init sequence as part of memory
> > > controller block initialization. Hence remapping of HDP registers
> > > needed for flush needs to happen earlier.
> > >
> > > This also fixes the AER error reported as Unsupported Request during
> > > driver load.
> >
> > I would say something like:
> >
> >   This prevents writes to unimplemented space, which would cause
> >   Unsupported Request errors.  Prior to 8795e182b02d ("PCI/portdrv:
> >   Don't disable AER reporting in get_port_device_capability()"), these
> >   errors occurred but were ignored.
> >
> > The write is the error; AER is just the reporting mechanism.
> >
> > > Link:
> > >
> > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugz
> > >
> > illa.kernel.org%2Fshow_bug.cgi%3Fid%3D216373&data=05%7C01%7Cal
> > exan
> > >
> > der.deucher%40amd.com%7C3306aa3e6a834f2d394808da86c3dfb1%7C3dd8
> > 961fe48
> > >
> > 84e608e11a82d994e183d%7C0%7C0%7C637970473081942953%7CUnknown%
> > 7CTWFpbGZ
> > >
> > sb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6M
> > n0%3
> > >
> > D%7C3000%7C%7C%7C&sdata=DFqggIRt4sKNjJB5bY14yi5oJ8I4szzndQD
> > blr6Vcr
> > > c%3D&reserved=0
> >
> > We need a cc: stable because 8795e182b02d ("PCI/portdrv: Don't disable AER
> > reporting in get_port_device_capability()") has already been backported to
> > at lealst these stable kernels:
> >
> >   5.10.137 5.15.61 5.18.18 5.19.2
> >
> > and these fixes need to go there as well.  So add something like this:
> >
> >   Fixes: 8795e182b02d ("PCI/portdrv: Don't disable AER reporting in
> > get_port_device_capability()")
> >   cc: stable at vger.kernel.org
> >
> > It's not that there was something wrong with 8795e182b02d and these
> > patches fix it; it's just that 8795e182b02d *exposed* an amdgpu problem
> > that was there all along.  But we need some way to connect with it.
>
> Will update the patch with these comments.  Also @tseewald at gmail.com can you please test this patch and confirm that it fixes things for you as well?

Sorry, ignore this.  This old email showed up at the top of my inbox
for some reason and I mixed up the threads.

Alex

>
> Alex
>
> >
> > > Reported-by: Tom Seewald <tseewald at gmail.com>
> > > Signed-off-by: Lijo Lazar <lijo.lazar at amd.com>