From: Huang Rui <ray.huang@amd.com>
To: Sinan Kaya <okaya@codeaurora.org>
Cc: amd-gfx@lists.freedesktop.org, timur@codeaurora.org,
sulrich@codeaurora.org, linux-arm-msm@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
"Alex Deucher" <alexander.deucher@amd.com>,
"Christian König" <christian.koenig@amd.com>,
"David (ChunMing) Zhou" <David1.Zhou@amd.com>,
"David Airlie" <airlied@linux.ie>,
"Felix Kuehling" <Felix.Kuehling@amd.com>,
"Monk Liu" <Monk.Liu@amd.com>, "Roger He" <Hongbo.He@amd.com>,
"Jim Qu" <Jim.Qu@amd.com>, "Emily Deng" <Emily.Deng@amd.com>,
"Feifei Xu" <Feifei.Xu@amd.com>,
"Tom St Denis" <tom.stdenis@amd.com>,
"David Panariti" <David.Panariti@amd.com>,
"open list:DRM DRIVERS" <dri-devel@lists.freedesktop.org>,
"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH V2] drm/amdgpu: limit DMA size to PAGE_SIZE for scatter-gather buffers
Date: Wed, 11 Apr 2018 14:26:03 +0800 [thread overview]
Message-ID: <20180411062602.GA29109@hr-amur2> (raw)
In-Reply-To: <1523394001-4615-1-git-send-email-okaya@codeaurora.org>
On Tue, Apr 10, 2018 at 04:59:55PM -0400, Sinan Kaya wrote:
> Code is expecing to observe the same number of buffers returned from
> dma_map_sg() function compared to sg_alloc_table_from_pages(). This
> doesn't hold true universally especially for systems with IOMMU.
>
> IOMMU driver tries to combine buffers into a single DMA address as much
> as it can. The right thing is to tell the DMA layer how much combining
> IOMMU can do.
>
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Sinan, I guess Christian's suggestion is to add amdgpu_device_init function
like here:
8<-------
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 0e798b3..9b96771 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2339,6 +2339,8 @@ int amdgpu_device_init(struct amdgpu_device *adev,
/* init the mode config */
drm_mode_config_init(adev->ddev);
+ dma_set_max_seg_size(adev->dev, PAGE_SIZE);
+
r = amdgpu_device_ip_init(adev);
if (r) {
/* failed in exclusive mode due to timeout */
8<-------
After that, we don't do it in each generation.
Thanks,
Ray
next prev parent reply other threads:[~2018-04-11 6:21 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-04-10 20:59 [PATCH V2] drm/amdgpu: limit DMA size to PAGE_SIZE for scatter-gather buffers Sinan Kaya
2018-04-11 6:26 ` Huang Rui [this message]
2018-04-11 9:17 ` Christian König
2018-04-11 12:03 ` Robin Murphy
2018-04-11 14:33 ` Sinan Kaya
2018-04-11 15:32 ` Robin Murphy
2018-04-12 6:26 ` Christoph Hellwig
2018-04-12 9:42 ` Christian König
2018-04-12 13:51 ` Robin Murphy
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=20180411062602.GA29109@hr-amur2 \
--to=ray.huang@amd.com \
--cc=David.Panariti@amd.com \
--cc=David1.Zhou@amd.com \
--cc=Emily.Deng@amd.com \
--cc=Feifei.Xu@amd.com \
--cc=Felix.Kuehling@amd.com \
--cc=Hongbo.He@amd.com \
--cc=Jim.Qu@amd.com \
--cc=Monk.Liu@amd.com \
--cc=airlied@linux.ie \
--cc=alexander.deucher@amd.com \
--cc=amd-gfx@lists.freedesktop.org \
--cc=christian.koenig@amd.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=okaya@codeaurora.org \
--cc=sulrich@codeaurora.org \
--cc=timur@codeaurora.org \
--cc=tom.stdenis@amd.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;
as well as URLs for NNTP newsgroup(s).