From: "hch@lst.de" <hch@lst.de>
To: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Cc: "Hellstrom, Thomas" <thomas.hellstrom@intel.com>,
"daniel@ffwll.ch" <daniel@ffwll.ch>,
"joonas.lahtinen@linux.intel.com"
<joonas.lahtinen@linux.intel.com>,
"Vivi, Rodrigo" <rodrigo.vivi@intel.com>,
"bob.beckett@collabora.com" <bob.beckett@collabora.com>,
"jani.nikula@linux.intel.com" <jani.nikula@linux.intel.com>,
"airlied@linux.ie" <airlied@linux.ie>, "hch@lst.de" <hch@lst.de>,
"Ursulin, Tvrtko" <tvrtko.ursulin@intel.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"dri-devel@lists.freedesktop.org"
<dri-devel@lists.freedesktop.org>,
"kernel@collabora.com" <kernel@collabora.com>,
"Auld, Matthew" <matthew.auld@intel.com>,
"intel-gfx@lists.freedesktop.org"
<intel-gfx@lists.freedesktop.org>
Subject: Re: [PATCH v5] drm/i915: stop using swiotlb
Date: Tue, 9 Aug 2022 20:54:03 +0200 [thread overview]
Message-ID: <20220809185403.GB15307@lst.de> (raw)
In-Reply-To: <db9f787e-c3e4-d353-da57-80cb7a135d86@linux.intel.com>
On Tue, Aug 09, 2022 at 12:36:50PM +0100, Tvrtko Ursulin wrote:
>
> Digging through git history at least running as Xen dom0 looks to have been
> impacted, but commits such as abb0deacb5a6 ("drm/i915: Fallback to single
> PAGE_SIZE segments for DMA remapping") are older and suggest problem was
> generic. 1625e7e549c5 ("drm/i915: make compact dma scatter lists creation
> work with SWIOTLB backend.") as well. So it looks it did work behind
> swiotlb despite those missing calls you highlighted.
Hmm. xen-swiotlb bounce buffers as soon as any single mapping that
straddles a Xen page size boundary. Could the magic value there
somehow made all mappings small enough to just avoid bounce buffering
for Xen by more or less accident?
next prev parent reply other threads:[~2022-08-09 19:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-26 15:39 [PATCH v5] drm/i915: stop using swiotlb Robert Beckett
2022-08-08 15:48 ` Hellstrom, Thomas
2022-08-09 11:36 ` Tvrtko Ursulin
2022-08-09 18:54 ` hch [this message]
2022-08-09 18:51 ` hch
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220809185403.GB15307@lst.de \
--to=hch@lst.de \
--cc=airlied@linux.ie \
--cc=bob.beckett@collabora.com \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=intel-gfx@lists.freedesktop.org \
--cc=jani.nikula@linux.intel.com \
--cc=joonas.lahtinen@linux.intel.com \
--cc=kernel@collabora.com \
--cc=linux-kernel@vger.kernel.org \
--cc=matthew.auld@intel.com \
--cc=rodrigo.vivi@intel.com \
--cc=thomas.hellstrom@intel.com \
--cc=tvrtko.ursulin@intel.com \
--cc=tvrtko.ursulin@linux.intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox