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

[Deucher, Alexander]

[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?

Alex

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