linux-kernel - Re: [PATCH v3 03/20] drm/msm/a6xx: Skip dumping SCRATCH registers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <CAF6AEGv9OVHBDF+XVNRr+ZtWijs+MDNUgw9zg0HbebuCQbHcZg@mail.gmail.com>
Date: Mon, 17 Nov 2025 07:44:05 -0800
From: Rob Clark <robdclark@...il.com>
To: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
Cc: Akhil P Oommen <akhilpo@....qualcomm.com>, Rob Clark <robin.clark@....qualcomm.com>, 
	Bjorn Andersson <andersson@...nel.org>, Konrad Dybcio <konradybcio@...nel.org>, 
	Sean Paul <sean@...rly.run>, Dmitry Baryshkov <lumag@...nel.org>, 
	Abhinav Kumar <abhinav.kumar@...ux.dev>, Jessica Zhang <jesszhan0024@...il.com>, 
	Marijn Suijten <marijn.suijten@...ainline.org>, David Airlie <airlied@...il.com>, 
	Simona Vetter <simona@...ll.ch>, Jonathan Marek <jonathan@...ek.ca>, 
	Jordan Crouse <jordan@...micpenguin.net>, Will Deacon <will@...nel.org>, 
	Robin Murphy <robin.murphy@....com>, Joerg Roedel <joro@...tes.org>, Rob Herring <robh@...nel.org>, 
	Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, 
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>, Maxime Ripard <mripard@...nel.org>, 
	Thomas Zimmermann <tzimmermann@...e.de>, Connor Abbott <cwabbott0@...il.com>, linux-arm-msm@...r.kernel.org, 
	linux-kernel@...r.kernel.org, dri-devel@...ts.freedesktop.org, 
	freedreno@...ts.freedesktop.org, linux-arm-kernel@...ts.infradead.org, 
	iommu@...ts.linux.dev, devicetree@...r.kernel.org, 
	Rob Clark <rob.clark@....qualcomm.com>
Subject: Re: [PATCH v3 03/20] drm/msm/a6xx: Skip dumping SCRATCH registers

On Mon, Nov 17, 2025 at 6:00 AM Konrad Dybcio
<konrad.dybcio@....qualcomm.com> wrote:
>
> On 11/14/25 12:29 AM, Akhil P Oommen wrote:
> > Crashdec doesn't require SCRATCH registers anymore for a6xx and newer
> > architectures. So skip dumping them during recovery.
> >
> > Suggested-by: Rob Clark <rob.clark@....qualcomm.com>
> > Signed-off-by: Akhil P Oommen <akhilpo@....qualcomm.com>
> > ---
>
> Looks like this changed in:
>
> https://gitlab.freedesktop.org/mesa/mesa/-/commit/95104707f189b2e1b06c855b563c1203b33da354

Crashdec finding estimated hang location based on CP registers dates
back prior to importing that code into mesa ~5yrs ago, fwiw.. and was
improved over the years to better handle IB prefetch since then.
Fwiw.

It does mean for gen8 we are going to need a CPU based fallback to
crashdumper to make smmu fault devcoredumps useful (since now
crashdumper is needed to capture CP regs), but we need that anyways.

BR,
-R

> and needs_seqno is never true now?
>
> Konrad