Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Mon, 23 Aug 2021 17:13:45 -0400
From:   Alyssa Rosenzweig <alyssa@collabora.com>
To:     Steven Price <steven.price@arm.com>
Cc:     Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
        dri-devel@lists.freedesktop.org, Rob Herring <robh@kernel.org>,
        Tomeu Vizoso <tomeu.vizoso@collabora.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>, linux-kernel@vger.kernel.org,
        Chris Morgan <macromorgan@hotmail.com>, stable@vger.kernel.org
Subject: Re: [PATCH 3/3] drm/panfrost: Clamp lock region to Bifrost minimum
Message-ID: <YSQPiQX8IOkJJSoY@maud>
References: <20210820213117.13050-1-alyssa.rosenzweig@collabora.com>
 <20210820213117.13050-4-alyssa.rosenzweig@collabora.com>
 <818b1a15-ddf4-461b-1d6a-cea539deaf76@arm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <818b1a15-ddf4-461b-1d6a-cea539deaf76@arm.com>
Precedence: bulk

> > When locking a region, we currently clamp to a PAGE_SIZE as the minimum
> > lock region. While this is valid for Midgard, it is invalid for Bifrost,
> 
> While the spec does seem to state it's invalid for Bifrost - kbase
> didn't bother with a lower clamp for a long time. I actually think this
> is in many ways more of a spec bug: i.e. implementation details of the
> round-up that the hardware does. But it's much safer following the spec
> ;) And it seems like kbase eventually caught up too.

Yeah, makes sense. Should I drop the Cc: stable in that case? If the
issue is purely theoretical.