From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id C89F74611C7 for ; Fri, 16 Oct 2026 12:25:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792153543; cv=none; b=vBXFtXEjQo5aLKQOIl9a9wmvi+wa4Sjq5CdXr/WlsU4bhqEhYP6jMXm24LwA9CPBVl8p6NXG5XL1DlL7nil0bZ1enw+wrg8Yjyvj88unYuGC479m+KpJWL0jXz+vMKL/4EhVOFRIiJp072bSmv0wQonCdZqVvxPv0uNyd7nGgV8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792153543; c=relaxed/simple; bh=krxKzyNI1ZYpileNc2uCsCIeFjKDXJ2c5kSdMOWJL38=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=exIxncS6D9ON3hph2sqnjY9xlwvwaOpcD8EjZUnjPKssMh+UwOheJDlUi+n6eiT6cukPWRSwdy5ZrsrAQluUFVJV2ie4yoJAyzoa86FrjTQsKGV1Cp6dSttjisYh4FNKfZlgk+iZfPM9/IGFtLpIa9Tk2DSHMg5g3LsnJb1HNfI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=NE0wR8zX; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="NE0wR8zX" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DC35C1516 for ; Fri, 16 Oct 2026 05:25:37 -0700 (PDT) Received: from [10.2.11.34] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E5A363F871 for ; Fri, 16 Oct 2026 05:25:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1792153541; bh=krxKzyNI1ZYpileNc2uCsCIeFjKDXJ2c5kSdMOWJL38=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NE0wR8zXsNDPwDPv29Rja8LPc2hgsmSlu8DIv04j1+3cgaWyIBoTidLphtTaA+00s iPY28dIJY5XnrcGPEx+PgCXrJXkQtlpQeWTB5fJSlB6Jo48Sr4vqEA2e8lG/ZiUYxj 2ii8k8n9KM15OebDQHgzpXNvF68glxRnsnKu1NdI= Date: Fri, 16 Oct 2026 13:25:29 +0100 From: Liviu Dudau To: Boris Brezillon Cc: Steven Price , Akash Goel , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Chia-I Wu , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] drm/panthor: Misc MMU fixes/robustness improvements Message-ID: References: <20260924-panthor-mmu-fixes-v1-0-e25f9b106466@collabora.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260924-panthor-mmu-fixes-v1-0-e25f9b106466@collabora.com> On Thu, Sep 24, 2026 at 02:30:42PM +0200, Boris Brezillon wrote: > The first commit is fixing a bug we've seen on v13 HW. Even though > we don't quite understand what happens (race in the flush-elimination > logic when flush requests are sent concurrently from the CPU and the > MCU), it seems that the downstream driver has always been doing a > flush+invalidate of RW caches from the start, and that we were doing > so up until the atomic page table update changes, so let's go back to > that state and leave the RO L1 caches untouched. > > The second patch a fix for a race that could very well happen if we > ever end up with a failure between the as_disable() and as_enable() > calls. We've not experienced this so far, but it seems worth plugging > the hole regardless. The last patch is a much more theoretical bug, > which would involve a buggy FW telling us that a CSG is suspended, > when it's actually. I've deliberately not added a Fixes tag on the > last one for this very reason, but I think it's worth staying on > the safe side by addressing this theoretical issue, still. > > Signed-off-by: Boris Brezillon > --- > Boris Brezillon (3): > drm/panthor: Don't invalidate OTHER caches > drm/panthor: Fully disable the AS even if it's going to be re-assigned > drm/panthor: Move cache-flush after UPDATE(UNMAPPED) > > drivers/gpu/drm/panthor/panthor_mmu.c | 43 ++++++++++++++++------------------- > 1 file changed, 20 insertions(+), 23 deletions(-) > --- > base-commit: 45585c3aa285854face65293acc95eff73063d6d > change-id: 20260924-panthor-mmu-fixes-a1832dc60908 > > Best regards, > -- > Boris Brezillon > Pushed the whole series into drm-misc-next-fixes after updating the comment on 1/3 as suggested by sashiko. Best regards, Liviu -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯