From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Tomasz Figa <tfiga@chromium.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>,
Dafna Hirschfeld <dafna.hirschfeld@collabora.com>,
Hans Verkuil <hverkuil-cisco@xs4all.nl>,
Ricardo Ribalda <ribalda@chromium.org>,
Christoph Hellwig <hch@lst.de>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
Collabora Kernel ML <kernel@collabora.com>
Subject: Re: [PATCHv3 8/8] videobuf2: handle non-contiguous DMA allocations
Date: Mon, 26 Jul 2021 13:10:55 +0900 [thread overview]
Message-ID: <YP41zzARXEXESEXE@google.com> (raw)
In-Reply-To: <CAAFQd5D6hSoLJaBMdV-fpzn43Y6qRULR4ckejrJp_89Qpe6Xnw@mail.gmail.com>
On (21/07/26 13:04), Tomasz Figa wrote:
> On Mon, Jul 26, 2021 at 12:59 PM Sergey Senozhatsky
> <senozhatsky@chromium.org> wrote:
> >
> > On (21/07/22 19:26), Dafna Hirschfeld wrote:
> > > Also, the 'cookie' cb returns buf->dma_addr which is not initialized for
> > > the noncontiguous api. So it is not clear how drivers should use the new api.
> > > Many drivers call vb2_dma_contig_plane_dma_addr which returns the cookie.
> >
> > Hmm, that's a good find. Is ->dma_addr the same as what we have in
> > sgt.sgl->dma_address for non-contig?
>
> Yes. As per [1]:
>
> "The return sg_table is guaranteed to have 1 single DMA mapped segment
> as indicated by sgt->nents, but it might have multiple CPU side
> segments as indicated by sgt->orig_nents."
Thanks. So the fix can look as follows:
---
static int vb2_dc_alloc_non_coherent(struct vb2_dc_buf *buf)
{
struct vb2_queue *q = buf->vb->vb2_queue;
buf->dma_sgt = dma_alloc_noncontiguous(buf->dev,
buf->size,
buf->dma_dir,
GFP_KERNEL | q->gfp_flags,
buf->attrs);
if (!buf->dma_sgt)
return -ENOMEM;
+ buf->dma_addr = sg_dma_address(buf->dma_sgt->sgl);
---
next prev parent reply other threads:[~2021-07-26 4:11 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-09 9:20 [PATCHv3 0/8] videobuf2: support new noncontiguous DMA API Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 1/8] videobuf2: rework vb2_mem_ops API Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 2/8] videobuf2: inverse buffer cache_hints flags Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 3/8] videobuf2: split buffer cache_hints initialisation Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 4/8] videobuf2: move cache_hints handling to allocators Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 5/8] videobuf2: add V4L2_MEMORY_FLAG_NON_COHERENT flag Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 6/8] videobuf2: add queue memory coherency parameter Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 7/8] videobuf2: handle V4L2_MEMORY_FLAG_NON_COHERENT flag Sergey Senozhatsky
2021-07-22 17:33 ` Dafna Hirschfeld
2021-07-26 1:40 ` Sergey Senozhatsky
2021-07-26 4:05 ` Sergey Senozhatsky
2021-07-26 4:20 ` Sergey Senozhatsky
2021-07-26 4:22 ` Tomasz Figa
2021-07-26 4:41 ` Sergey Senozhatsky
2021-07-09 9:20 ` [PATCHv3 8/8] videobuf2: handle non-contiguous DMA allocations Sergey Senozhatsky
2021-07-22 17:26 ` Dafna Hirschfeld
2021-07-26 3:59 ` Sergey Senozhatsky
2021-07-26 4:04 ` Tomasz Figa
2021-07-26 4:10 ` Sergey Senozhatsky [this message]
2021-07-27 7:06 ` Sergey Senozhatsky
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=YP41zzARXEXESEXE@google.com \
--to=senozhatsky@chromium.org \
--cc=dafna.hirschfeld@collabora.com \
--cc=hch@lst.de \
--cc=hverkuil-cisco@xs4all.nl \
--cc=kernel@collabora.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=mchehab@kernel.org \
--cc=ribalda@chromium.org \
--cc=tfiga@chromium.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).