2012/1/10 Rob Clark :
> On Mon, Jan 9, 2012 at 7:34 PM, InKi Dae wrote:
>> 2012/1/10 Rob Clark :
>>> On Mon, Jan 9, 2012 at 4:10 AM, InKi Dae wrote:
note : in case of sharing a buffer between v4l2 and drm driver, the
memory info would be copied vb2_xx_buf to xx_gem or xx_gem to
vb2
2012/1/10 InKi Dae :
> 2012/1/10 Semwal, Sumit :
>> On Tue, Jan 10, 2012 at 7:44 AM, Rob Clark wrote:
>>> On Mon, Jan 9, 2012 at 7:34 PM, InKi Dae wrote:
2012/1/10 Rob Clark :
at least with no IOMMU, the memory information(containing physical
memory address) would be copied to vb2_
2012/1/10 Semwal, Sumit :
> On Tue, Jan 10, 2012 at 7:44 AM, Rob Clark wrote:
>> On Mon, Jan 9, 2012 at 7:34 PM, InKi Dae wrote:
>>> 2012/1/10 Rob Clark :
>>> at least with no IOMMU, the memory information(containing physical
>>> memory address) would be copied to vb2_xx_buf object if drm gem
>>>
On Tue, Jan 10, 2012 at 7:44 AM, Rob Clark wrote:
> On Mon, Jan 9, 2012 at 7:34 PM, InKi Dae wrote:
>> 2012/1/10 Rob Clark :
>> at least with no IOMMU, the memory information(containing physical
>> memory address) would be copied to vb2_xx_buf object if drm gem
>> exported its own buffer and vb2
On Mon, Jan 9, 2012 at 7:34 PM, InKi Dae wrote:
> 2012/1/10 Rob Clark :
>> On Mon, Jan 9, 2012 at 4:10 AM, InKi Dae wrote:
>>> note : in case of sharing a buffer between v4l2 and drm driver, the
>>> memory info would be copied vb2_xx_buf to xx_gem or xx_gem to
>>> vb2_xx_buf through sg table. in
2012/1/10 Rob Clark :
> On Mon, Jan 9, 2012 at 4:10 AM, InKi Dae wrote:
>> note : in case of sharing a buffer between v4l2 and drm driver, the
>> memory info would be copied vb2_xx_buf to xx_gem or xx_gem to
>> vb2_xx_buf through sg table. in this case, only memory info is used to
>> share, not so
On Mon, Jan 09, 2012 at 09:06:56PM +0900, InKi Dae wrote:
> 2012/1/9 Daniel Vetter :
> > On Mon, Jan 09, 2012 at 07:10:25PM +0900, InKi Dae wrote:
> >> 2012/1/9 Daniel Vetter :
> >> > On Mon, Jan 09, 2012 at 03:20:48PM +0900, InKi Dae wrote:
> >> >> I has test dmabuf based drm gem module for exynos
On Mon, Jan 9, 2012 at 4:10 AM, InKi Dae wrote:
> note : in case of sharing a buffer between v4l2 and drm driver, the
> memory info would be copied vb2_xx_buf to xx_gem or xx_gem to
> vb2_xx_buf through sg table. in this case, only memory info is used to
> share, not some objects.
which v4l2/vb2
2012/1/9 Daniel Vetter :
> On Mon, Jan 09, 2012 at 07:10:25PM +0900, InKi Dae wrote:
>> 2012/1/9 Daniel Vetter :
>> > On Mon, Jan 09, 2012 at 03:20:48PM +0900, InKi Dae wrote:
>> >> I has test dmabuf based drm gem module for exynos and I found one problem.
>> >> you can refer to this test repositor
On Mon, Jan 09, 2012 at 07:10:25PM +0900, InKi Dae wrote:
> 2012/1/9 Daniel Vetter :
> > On Mon, Jan 09, 2012 at 03:20:48PM +0900, InKi Dae wrote:
> >> I has test dmabuf based drm gem module for exynos and I found one problem.
> >> you can refer to this test repository:
> >> http://git.infradead.or
2012/1/9 Daniel Vetter :
> On Mon, Jan 09, 2012 at 03:20:48PM +0900, InKi Dae wrote:
>> I has test dmabuf based drm gem module for exynos and I found one problem.
>> you can refer to this test repository:
>> http://git.infradead.org/users/kmpark/linux-samsung/shortlog/refs/heads/exynos-drm-dmabuf
>
On Mon, Jan 9, 2012 at 8:10 AM, Daniel Vetter wrote:
> On Mon, Jan 09, 2012 at 03:20:48PM +0900, InKi Dae wrote:
>> I has test dmabuf based drm gem module for exynos and I found one problem.
>> you can refer to this test repository:
>> http://git.infradead.org/users/kmpark/linux-samsung/shortlog/r
On Mon, Jan 09, 2012 at 03:20:48PM +0900, InKi Dae wrote:
> I has test dmabuf based drm gem module for exynos and I found one problem.
> you can refer to this test repository:
> http://git.infradead.org/users/kmpark/linux-samsung/shortlog/refs/heads/exynos-drm-dmabuf
>
> at this repository, I adde
2011/12/2 Sumit Semwal :
> This is the first step in defining a dma buffer sharing mechanism.
>
> A new buffer object dma_buf is added, with operations and API to allow easy
> sharing of this buffer object across devices.
>
> The framework allows:
> - different devices to 'attach' themselves to thi
On Sun, Jan 1, 2012 at 2:53 PM, Sakari Ailus wrote:
> Hi Arnd,
>
> On Tue, Dec 20, 2011 at 03:36:49PM +, Arnd Bergmann wrote:
>> On Tuesday 20 December 2011, Sakari Ailus wrote:
>> > (I'm jumping into the discussion in the middle, and might miss something
>> > that has already been talked abou
Hi Arnd,
On Tue, Dec 20, 2011 at 03:36:49PM +, Arnd Bergmann wrote:
> On Tuesday 20 December 2011, Sakari Ailus wrote:
> > (I'm jumping into the discussion in the middle, and might miss something
> > that has already been talked about. I still hope what I'm about to say is
> > relevant. :-))
>
On Fri, Dec 23, 2011 at 4:00 AM, Semwal, Sumit wrote:
> On Wed, Dec 21, 2011 at 10:57 PM, Arnd Bergmann wrote:
>> On Tuesday 20 December 2011, Daniel Vetter wrote:
>>> > I'm thinking for a first version, we can get enough mileage out of it by
>>> > saying:
>>> > 1) only exporter can mmap to user
On Wed, Dec 21, 2011 at 10:57 PM, Arnd Bergmann wrote:
> On Tuesday 20 December 2011, Daniel Vetter wrote:
>> > I'm thinking for a first version, we can get enough mileage out of it by
>> > saying:
>> > 1) only exporter can mmap to userspace
>> > 2) only importers that do not need CPU access to b
On Wed, Dec 21, 2011 at 05:27:16PM +, Arnd Bergmann wrote:
> On Tuesday 20 December 2011, Daniel Vetter wrote:
> > It also sounds like that at least for proper userspace mmap support we'd
> > need some dma api extensions on at least arm, and that might take a while
> > ...
>
> I think it's act
On Tuesday 20 December 2011, Daniel Vetter wrote:
> > I'm thinking for a first version, we can get enough mileage out of it by
> > saying:
> > 1) only exporter can mmap to userspace
> > 2) only importers that do not need CPU access to buffer..
Ok, that sounds possible. The alternative to this wou
On Tue, Dec 20, 2011 at 10:41:45AM -0600, Rob Clark wrote:
> On Tue, Dec 20, 2011 at 9:41 AM, Arnd Bergmann wrote:
> > On Monday 19 December 2011, Semwal, Sumit wrote:
> >> I didn't see a consensus on whether dma_buf should enforce some form
> >> of serialization within the API - so atleast for v1
On Tue, Dec 20, 2011 at 9:41 AM, Arnd Bergmann wrote:
> On Monday 19 December 2011, Semwal, Sumit wrote:
>> I didn't see a consensus on whether dma_buf should enforce some form
>> of serialization within the API - so atleast for v1 of dma-buf, I
>> propose to 'not' impose a restriction, and we can
On Monday 19 December 2011, Semwal, Sumit wrote:
> I didn't see a consensus on whether dma_buf should enforce some form
> of serialization within the API - so atleast for v1 of dma-buf, I
> propose to 'not' impose a restriction, and we can tackle it (add new
> ops or enforce as design?) whenever we
On Tuesday 20 December 2011, Sakari Ailus wrote:
> (I'm jumping into the discussion in the middle, and might miss something
> that has already been talked about. I still hope what I'm about to say is
> relevant. :-))
It certainly is relevant.
> In subsystems such as V4L2 where drivers deal with s
On Tue, Dec 20, 2011 at 4:05 AM, Robert Morell wrote:
>
> One of the goals of this project is to unify the fragmented space of the
> ARM SoC memory managers so that each vendor doesn't implement their own,
> and they can all be closer to mainline.
That is a very good objective.
> I fear that res
Hi Arnd,
On Fri, Dec 09, 2011 at 02:13:03PM +, Arnd Bergmann wrote:
> On Thursday 08 December 2011, Daniel Vetter wrote:
> > > c) only allowing streaming mappings, even if those are non-coherent
> > > (requiring strict serialization between CPU (in-kernel) and dma users of
> > > the buffer)
>
On Tue, Dec 13, 2011 at 07:10:02AM -0800, Arnd Bergmann wrote:
> On Monday 12 December 2011, Robert Morell wrote:
> > >
> > > Doing a buffer sharing with something that is not GPL is not fun, as, if
> > > any
> > > issue rises there, it would be impossible to discover if the problem is
> > > eit
Hi Arnd, Daniel,
On Mon, Dec 12, 2011 at 10:18 PM, Arnd Bergmann wrote:
> On Saturday 10 December 2011, Daniel Vetter wrote:
>> If userspace (through some driver calls)
>> tries to do stupid things, it'll just get garbage. See
>> Message-ID:
>>
>> for my reasons why it think this is the right w
On Monday 12 December 2011, Robert Morell wrote:
> >
> > Doing a buffer sharing with something that is not GPL is not fun, as, if any
> > issue rises there, it would be impossible to discover if the problem is
> > either
> > at the closed-source driver or at the open source one. At the time I was
(I've been away for the past two weeks, so I'm only now catching up)
On Thursday 08 December 2011 22:44:08 Daniel Vetter wrote:
> On Wed, Dec 7, 2011 at 14:40, Arnd Bergmann wrote:
> > On Wednesday 07 December 2011, Semwal, Sumit wrote:
> >> Thanks for the excellent discussion - it indeed is ver
On Sat, Dec 10, 2011 at 03:13:06AM -0800, Mauro Carvalho Chehab wrote:
> On 09-12-2011 20:50, Robert Morell wrote:
> > On Mon, Dec 05, 2011 at 09:18:48AM -0800, Arnd Bergmann wrote:
> >> On Friday 02 December 2011, Sumit Semwal wrote:
> >>> This is the first step in defining a dma buffer sharing me
On Saturday 10 December 2011, Daniel Vetter wrote:
> If userspace (through some driver calls)
> tries to do stupid things, it'll just get garbage. See
> Message-ID:
>
> for my reasons why it think this is the right way to go forward. So in
> essence I'm really interested in the reasons why you wa
On 09-12-2011 20:50, Robert Morell wrote:
On Mon, Dec 05, 2011 at 09:18:48AM -0800, Arnd Bergmann wrote:
On Friday 02 December 2011, Sumit Semwal wrote:
This is the first step in defining a dma buffer sharing mechanism.
[...]
+ return dmabuf;
+}
+EXPORT_SYMBOL(dma_buf_export);
I a
On Fri, Dec 9, 2011 at 15:24, Alan Cox wrote:
>> I still don't think that's possible. Please explain how you expect
>> to change the semantics of the streaming mapping API to allow multiple
>> mappers without having explicit serialization points that are visible
>> to all users. For simplicity, le
On Mon, Dec 05, 2011 at 09:18:48AM -0800, Arnd Bergmann wrote:
> On Friday 02 December 2011, Sumit Semwal wrote:
> > This is the first step in defining a dma buffer sharing mechanism.
>
[...]
>
> > + return dmabuf;
> > +}
> > +EXPORT_SYMBOL(dma_buf_export);
>
> I agree with Konrad, this should
> I still don't think that's possible. Please explain how you expect
> to change the semantics of the streaming mapping API to allow multiple
> mappers without having explicit serialization points that are visible
> to all users. For simplicity, let's assume a cache coherent system
I would agree.
On Thursday 08 December 2011, Daniel Vetter wrote:
> > c) only allowing streaming mappings, even if those are non-coherent
> > (requiring strict serialization between CPU (in-kernel) and dma users of
> > the buffer)
>
> I think only allowing streaming access makes the most sense:
> - I don't see m
On Wed, Dec 7, 2011 at 14:40, Arnd Bergmann wrote:
> On Wednesday 07 December 2011, Semwal, Sumit wrote:
>> Thanks for the excellent discussion - it indeed is very good learning
>> for the relatively-inexperienced me :)
>>
>> So, for the purpose of dma-buf framework, could I summarize the
>> follo
On Wednesday 07 December 2011, Semwal, Sumit wrote:
> Thanks for the excellent discussion - it indeed is very good learning
> for the relatively-inexperienced me :)
>
> So, for the purpose of dma-buf framework, could I summarize the
> following and rework accordingly?:
> 1. remove mmap() dma_buf_o
Hi Daniel, Rob,
On Tue, Dec 6, 2011 at 3:41 AM, Rob Clark wrote:
> On Mon, Dec 5, 2011 at 3:23 PM, Daniel Vetter wrote:
>> On Mon, Dec 05, 2011 at 02:46:47PM -0600, Rob Clark wrote:
>>> On Mon, Dec 5, 2011 at 11:18 AM, Arnd Bergmann wrote:
>>> > In the patch 2, you have a section about migrati
On Wednesday 07 December 2011, Semwal, Sumit wrote:
> Right; that would be ideal, but we may not be able to ask each user to
> do so - especially when the sharing part might be interspersed in
> existing buffer handling code. So for now, I would like to keep it as
> it-is.
Ok, fair enough. It cert
On Wed, Dec 7, 2011 at 3:41 PM, Arnd Bergmann wrote:
> On Wednesday 07 December 2011, Semwal, Sumit wrote:
>> >
>> > Do you have a use case for making the interface compile-time disabled?
>> > I had assumed that any code using it would make no sense if it's not
>> > available so you don't actually
On Wednesday 07 December 2011, Semwal, Sumit wrote:
> >
> > Do you have a use case for making the interface compile-time disabled?
> > I had assumed that any code using it would make no sense if it's not
> > available so you don't actually need this.
>
> Ok. Though if we keep the interface compile-
Hi Arnd,
Thanks for your review!
On Mon, Dec 5, 2011 at 10:48 PM, Arnd Bergmann wrote:
> On Friday 02 December 2011, Sumit Semwal wrote:
>> This is the first step in defining a dma buffer sharing mechanism.
>
> This looks very nice, but there are a few things I don't understand yet
> and a bunch
On Tue, Dec 06, 2011 at 01:16:58PM +, Arnd Bergmann wrote:
> On Monday 05 December 2011, Rob Clark wrote:
> > > On the topic of a coherency model for dmabuf, I think we need to look at
> > > dma_buf_attachment_map/unmap (and also the mmap variants cpu_start and
> > > cpu_finish or whatever they
On Monday 05 December 2011, Rob Clark wrote:
> > On the topic of a coherency model for dmabuf, I think we need to look at
> > dma_buf_attachment_map/unmap (and also the mmap variants cpu_start and
> > cpu_finish or whatever they might get called) as barriers:
> >
> > So after a dma_buf_map, all pre
On Mon, Dec 5, 2011 at 4:09 PM, Arnd Bergmann wrote:
> On Monday 05 December 2011 14:46:47 Rob Clark wrote:
>> I sort of preferred having the DMABUF shim because that lets you pass
>> a buffer around userspace without the receiving code knowing about a
>> device specific API. But the problem I ev
On Mon, Dec 05, 2011 at 11:04:09PM +0100, Arnd Bergmann wrote:
> On Monday 05 December 2011 21:58:39 Daniel Vetter wrote:
> > On Mon, Dec 05, 2011 at 08:29:49PM +0100, Arnd Bergmann wrote:
> > > ...
> >
> > Thanks a lot for this excellent overview. I think at least for the first
> > version of dmab
On Mon, Dec 05, 2011 at 04:11:46PM -0600, Rob Clark wrote:
> On Mon, Dec 5, 2011 at 3:23 PM, Daniel Vetter wrote:
> > On Mon, Dec 05, 2011 at 02:46:47PM -0600, Rob Clark wrote:
> >> I sort of preferred having the DMABUF shim because that lets you pass
> >> a buffer around userspace without the rec
On Mon, Dec 5, 2011 at 4:09 PM, Arnd Bergmann wrote:
>>
>> https://github.com/robclark/kernel-omap4/commits/dmabuf
>
> Ok, thanks. I think it would be good to post these for reference
> in v3, with a clear indication that they are not being submitted
> for discussion/inclusion yet.
btw, don't loo
On Mon, Dec 5, 2011 at 3:23 PM, Daniel Vetter wrote:
> On Mon, Dec 05, 2011 at 02:46:47PM -0600, Rob Clark wrote:
>> On Mon, Dec 5, 2011 at 11:18 AM, Arnd Bergmann wrote:
>> > In the patch 2, you have a section about migration that mentions that
>> > it is possible to export a buffer that can be
On Monday 05 December 2011 14:46:47 Rob Clark wrote:
> On Mon, Dec 5, 2011 at 11:18 AM, Arnd Bergmann wrote:
> > On Friday 02 December 2011, Sumit Semwal wrote:
> >> This is the first step in defining a dma buffer sharing mechanism.
> >
> > This looks very nice, but there are a few things I don't
On Monday 05 December 2011 21:58:39 Daniel Vetter wrote:
> On Mon, Dec 05, 2011 at 08:29:49PM +0100, Arnd Bergmann wrote:
> > ...
>
> Thanks a lot for this excellent overview. I think at least for the first
> version of dmabuf we should drop the sync_* interfaces and simply require
> users to brac
On Mon, Dec 05, 2011 at 02:46:47PM -0600, Rob Clark wrote:
> On Mon, Dec 5, 2011 at 11:18 AM, Arnd Bergmann wrote:
> > In the patch 2, you have a section about migration that mentions that
> > it is possible to export a buffer that can be migrated after it
> > is already mapped into one user drive
On Mon, Dec 05, 2011 at 08:29:49PM +0100, Arnd Bergmann wrote:
> On Monday 05 December 2011 19:55:44 Daniel Vetter wrote:
> > > The only way to solve this that I can think of right now is to
> > > mandate that the mappings are all coherent (i.e. noncachable
> > > on noncoherent architectures like A
On Mon, Dec 5, 2011 at 11:18 AM, Arnd Bergmann wrote:
> On Friday 02 December 2011, Sumit Semwal wrote:
>> This is the first step in defining a dma buffer sharing mechanism.
>
> This looks very nice, but there are a few things I don't understand yet
> and a bunch of trivial comments I have about t
On Monday 05 December 2011 19:55:44 Daniel Vetter wrote:
> > The only way to solve this that I can think of right now is to
> > mandate that the mappings are all coherent (i.e. noncachable
> > on noncoherent architectures like ARM). If you do that, you no
> > longer need the sync_sg_for_* calls.
>
On Mon, Dec 05, 2011 at 05:18:48PM +, Arnd Bergmann wrote:
> On Friday 02 December 2011, Sumit Semwal wrote:
> > + /* allow allocator to take care of cache ops */
> > + void (*sync_sg_for_cpu) (struct dma_buf *, struct device *);
> > + void (*sync_sg_for_device)(struct dma_buf *, struct d
On Friday 02 December 2011, Sumit Semwal wrote:
> This is the first step in defining a dma buffer sharing mechanism.
This looks very nice, but there are a few things I don't understand yet
and a bunch of trivial comments I have about things I spotted.
Do you have prototype exporter and consumer d
Hi Konrad,
On Fri, Dec 2, 2011 at 10:41 PM, Konrad Rzeszutek Wilk
wrote:
> On Fri, Dec 02, 2011 at 02:27:31PM +0530, Sumit Semwal wrote:
>> This is the first step in defining a dma buffer sharing mechanism.
>>
>>
>> [1]: https://wiki.linaro.org/OfficeofCTO/MemoryManagement
>> [2]: http://lwn.net
On Fri, Dec 02, 2011 at 02:27:31PM +0530, Sumit Semwal wrote:
> This is the first step in defining a dma buffer sharing mechanism.
>
> A new buffer object dma_buf is added, with operations and API to allow easy
> sharing of this buffer object across devices.
>
> The framework allows:
> - differen
This is the first step in defining a dma buffer sharing mechanism.
A new buffer object dma_buf is added, with operations and API to allow easy
sharing of this buffer object across devices.
The framework allows:
- different devices to 'attach' themselves to this buffer, to facilitate
backing sto
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