From: Steven Price <steven.price@arm.com>
To: dri-devel@lists.freedesktop.org,
Alyssa Rosenzweig <alyssa@collabora.com>
Cc: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>,
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>
Subject: Re: [PATCH 2/3] drm/panfrost: Use u64 for size in lock_region
Date: Mon, 23 Aug 2021 22:57:56 +0100 [thread overview]
Message-ID: <77CFD756-7F02-4CBA-9E58-3EDA2167620E@arm.com> (raw)
In-Reply-To: <YSQO7exgqnk0ZLJT@maud>
On 23 August 2021 22:11:09 BST, Alyssa Rosenzweig <alyssa@collabora.com> wrote:
>> > Mali virtual addresses are 48-bit. Use a u64 instead of size_t to ensure
>> > we can express the "lock everything" condition as ~0ULL without relying
>> > on platform-specific behaviour.
>>
>> 'platform-specific behaviour' makes it sound like this is something to
>> do with a particular board. This is 32bit/64bit - it's going to be
>> broken on 32bit: large lock regions are not going to work.
>
>Oh, my. I used the term as a weasel word since the spec is loose on how
>big a size_t actually is. But if this is causing actual breakage on
>armv7 we're in trouble. I'll add a Cc stable tag on v2, unless the Fixes
>implies that?
The usual practice is to put CC: stable in the commit message or the fixes tag (no need to actually CC the stable email address). So just Fixes: should work
>Thanks for pointing this out.
It's not actually quite so bad as it could be as >4GB regions are unlikely (especially on 32bit), but the GPU does of course support such a thing.
Thanks,
Steve
next prev parent reply other threads:[~2021-08-23 21:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 21:31 [PATCH 0/3] drm/panfrost: Bug fixes for lock_region Alyssa Rosenzweig
2021-08-20 21:31 ` [PATCH 1/3] drm/panfrost: Simplify lock_region calculation Alyssa Rosenzweig
2021-08-23 9:40 ` Steven Price
2021-08-23 21:09 ` Alyssa Rosenzweig
2021-08-23 21:54 ` Steven Price
2021-08-20 21:31 ` [PATCH 2/3] drm/panfrost: Use u64 for size in lock_region Alyssa Rosenzweig
2021-08-23 9:40 ` Steven Price
2021-08-23 21:11 ` Alyssa Rosenzweig
2021-08-23 21:57 ` Steven Price [this message]
2021-08-20 21:31 ` [PATCH 3/3] drm/panfrost: Clamp lock region to Bifrost minimum Alyssa Rosenzweig
2021-08-23 9:40 ` Steven Price
2021-08-23 21:13 ` Alyssa Rosenzweig
2021-08-23 22:02 ` Steven Price
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