From: Daniel Vetter <daniel@ffwll.ch>
To: "Christian König" <ckoenig.leichtzumerken@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
dri-devel <dri-devel@lists.freedesktop.org>,
"moderated list:DMA BUFFER SHARING FRAMEWORK"
<linaro-mm-sig@lists.linaro.org>, Linux MM <linux-mm@kvack.org>,
"open list:DMA BUFFER SHARING FRAMEWORK"
<linux-media@vger.kernel.org>
Subject: Re: [PATCH 1/2] drm/shmem-helpers: revert "Redirect mmap for imported dma-buf"
Date: Tue, 15 Sep 2020 12:39:39 +0200 [thread overview]
Message-ID: <CAKMK7uHnZgCBUBQ-5D7gCj1v3Z4wKkeO91tefAoJE1B49JFtww@mail.gmail.com> (raw)
In-Reply-To: <20200914132920.59183-2-christian.koenig@amd.com>
On Mon, Sep 14, 2020 at 3:29 PM Christian König
<ckoenig.leichtzumerken@gmail.com> wrote:
>
> This reverts commit 26d3ac3cb04d171a861952e89324e347598a347f.
>
> We need to figure out if dma_buf_mmap() is valid or not first.
>
> Signed-off-by: Christian König <christian.koenig@amd.com>
The trouble is that doing dma-buf mmap by looking at the struct pages
behind the sg list and just inserting those into userspace doesn't
really work any better. You still won't get the unmap_mapping_range
and hence pte shoot-down. So maybe dma_buf_mmap forwarding doesn't
work, but this doesn't make it any better.
Also commit message should probably explain a bit the context here,
not a lot of people have been in our private discussion on this.
-Daniel
> ---
> drivers/gpu/drm/drm_gem_shmem_helper.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index 0a952f27c184..cd727343f72b 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -594,9 +594,6 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
> /* Remove the fake offset */
> vma->vm_pgoff -= drm_vma_node_start(&obj->vma_node);
>
> - if (obj->import_attach)
> - return dma_buf_mmap(obj->dma_buf, vma, 0);
> -
> shmem = to_drm_gem_shmem_obj(obj);
>
> ret = drm_gem_shmem_get_pages(shmem);
> --
> 2.17.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
next prev parent reply other threads:[~2020-09-15 10:40 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-14 13:29 Changing vma->vm_file in dma_buf_mmap() Christian König
2020-09-14 13:29 ` [PATCH 1/2] drm/shmem-helpers: revert "Redirect mmap for imported dma-buf" Christian König
2020-09-15 10:39 ` Daniel Vetter [this message]
2020-09-15 11:03 ` Christian König
2020-09-15 11:07 ` Daniel Vetter
2020-09-14 13:29 ` [PATCH 2/2] mm: introduce vma_set_file function Christian König
2020-09-15 9:19 ` kernel test robot
2020-09-15 11:57 ` kernel test robot
2020-09-14 13:30 ` Changing vma->vm_file in dma_buf_mmap() Christian König
2020-09-14 14:06 ` Jason Gunthorpe
2020-09-14 18:26 ` Christian König
2020-09-16 9:53 ` Daniel Vetter
[not found] ` <fc8f2af7-9fc2-cb55-3065-75a4060b7c82@amd.com>
[not found] ` <b621db68-30b9-cc3f-c2c0-237a7fe4db09@amd.com>
2020-09-16 12:41 ` Daniel Vetter
2020-09-16 14:07 ` Jason Gunthorpe
2020-09-16 14:14 ` Christian König
2020-09-16 15:24 ` Daniel Vetter
2020-09-16 15:31 ` [Linaro-mm-sig] " Christian König
2020-09-17 6:23 ` Daniel Vetter
2020-09-17 7:11 ` Christian König
2020-09-17 8:09 ` Daniel Vetter
2020-09-17 11:31 ` Jason Gunthorpe
2020-09-17 12:03 ` Christian König
2020-09-17 12:18 ` Jason Gunthorpe
2020-09-17 12:24 ` Christian König
2020-09-17 12:26 ` Daniel Vetter
2020-09-17 14:35 ` Jason Gunthorpe
2020-09-17 14:54 ` Christian König
2020-09-17 15:24 ` Jason Gunthorpe
2020-09-17 15:37 ` Daniel Vetter
2020-09-17 16:06 ` Christian König
2020-09-17 16:39 ` Jason Gunthorpe
2020-09-17 17:23 ` Daniel Vetter
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=CAKMK7uHnZgCBUBQ-5D7gCj1v3Z4wKkeO91tefAoJE1B49JFtww@mail.gmail.com \
--to=daniel@ffwll.ch \
--cc=akpm@linux-foundation.org \
--cc=ckoenig.leichtzumerken@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=linaro-mm-sig@lists.linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=linux-mm@kvack.org \
/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).