2019-02-08 15:32:48

by Federico Vaga

[permalink] [raw]
Subject: [PATCH] doc:dmaengine: clarify DMA desc. pointer after submission

It clarifies that the DMA description pointer returned by
`dmaengine_prep_*` function should not be used after submission.

Signed-off-by: Federico Vaga <[email protected]>
---
Documentation/driver-api/dmaengine/client.rst | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst
index fbbb2831f29f..d728e50105eb 100644
--- a/Documentation/driver-api/dmaengine/client.rst
+++ b/Documentation/driver-api/dmaengine/client.rst
@@ -168,6 +168,13 @@ The details of these operations are:
dmaengine_submit() will not start the DMA operation, it merely adds
it to the pending queue. For this, see step 5, dma_async_issue_pending.

+ .. note::
+
+ After calling ``dmaengine_submit()`` the submitted transfer descriptor
+ (``struct dma_async_tx_descriptor``) belongs to the DMA engine.
+ Consequentially, the client must consider invalid the pointer to that
+ descriptor.
+
5. Issue pending DMA requests and wait for callback notification

The transactions in the pending queue can be activated by calling the
--
2.15.0



2019-02-11 11:55:33

by Vinod Koul

[permalink] [raw]
Subject: Re: [PATCH] doc:dmaengine: clarify DMA desc. pointer after submission

On 08-02-19, 16:30, Federico Vaga wrote:
> It clarifies that the DMA description pointer returned by
> `dmaengine_prep_*` function should not be used after submission.
>
> Signed-off-by: Federico Vaga <[email protected]>
> ---
> Documentation/driver-api/dmaengine/client.rst | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst
> index fbbb2831f29f..d728e50105eb 100644
> --- a/Documentation/driver-api/dmaengine/client.rst
> +++ b/Documentation/driver-api/dmaengine/client.rst
> @@ -168,6 +168,13 @@ The details of these operations are:
> dmaengine_submit() will not start the DMA operation, it merely adds
> it to the pending queue. For this, see step 5, dma_async_issue_pending.
>
> + .. note::
> +
> + After calling ``dmaengine_submit()`` the submitted transfer descriptor
> + (``struct dma_async_tx_descriptor``) belongs to the DMA engine.
> + Consequentially, the client must consider invalid the pointer to that

Consequently

> + descriptor.
> +

Applied after fixing the typo and added tag as Documentation: dmaengine...

> 5. Issue pending DMA requests and wait for callback notification
>
> The transactions in the pending queue can be activated by calling the
> --
> 2.15.0

--
~Vinod

2019-02-11 12:12:21

by Federico Vaga

[permalink] [raw]
Subject: Re: [PATCH] doc:dmaengine: clarify DMA desc. pointer after submission

On Monday, February 11, 2019 12:54:11 PM CET Vinod Koul wrote:
> On 08-02-19, 16:30, Federico Vaga wrote:
> > It clarifies that the DMA description pointer returned by
> > `dmaengine_prep_*` function should not be used after submission.
> >
> > Signed-off-by: Federico Vaga <[email protected]>
> > ---
> >
> > Documentation/driver-api/dmaengine/client.rst | 7 +++++++
> > 1 file changed, 7 insertions(+)
> >
> > diff --git a/Documentation/driver-api/dmaengine/client.rst
> > b/Documentation/driver-api/dmaengine/client.rst index
> > fbbb2831f29f..d728e50105eb 100644
> > --- a/Documentation/driver-api/dmaengine/client.rst
> > +++ b/Documentation/driver-api/dmaengine/client.rst
> >
> > @@ -168,6 +168,13 @@ The details of these operations are:
> > dmaengine_submit() will not start the DMA operation, it merely adds
> > it to the pending queue. For this, see step 5,
> > dma_async_issue_pending.
> >
> > + .. note::
> > +
> > + After calling ``dmaengine_submit()`` the submitted transfer
> > descriptor + (``struct dma_async_tx_descriptor``) belongs to the DMA
> > engine. + Consequentially, the client must consider invalid the
> > pointer to that
> Consequently

I'm not a native speaker but consequentially and consequently should be
synonymous. As fa as I understood. but I do not mind to change it if you think
is better.

> > + descriptor.
> > +
>
> Applied after fixing the typo and added tag as Documentation: dmaengine...

I used doc to make the string shorter

>
> > 5. Issue pending DMA requests and wait for callback notification
> >
> > The transactions in the pending queue can be activated by calling the





2019-02-11 15:41:47

by Jonathan Corbet

[permalink] [raw]
Subject: Re: [PATCH] doc:dmaengine: clarify DMA desc. pointer after submission

On Fri, 8 Feb 2019 16:30:38 +0100
Federico Vaga <[email protected]> wrote:

> It clarifies that the DMA description pointer returned by
> `dmaengine_prep_*` function should not be used after submission.
>
> Signed-off-by: Federico Vaga <[email protected]>
> ---
> Documentation/driver-api/dmaengine/client.rst | 7 +++++++
> 1 file changed, 7 insertions(+)
>
> diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst
> index fbbb2831f29f..d728e50105eb 100644
> --- a/Documentation/driver-api/dmaengine/client.rst
> +++ b/Documentation/driver-api/dmaengine/client.rst
> @@ -168,6 +168,13 @@ The details of these operations are:
> dmaengine_submit() will not start the DMA operation, it merely adds
> it to the pending queue. For this, see step 5, dma_async_issue_pending.
>
> + .. note::
> +
> + After calling ``dmaengine_submit()`` the submitted transfer descriptor
> + (``struct dma_async_tx_descriptor``) belongs to the DMA engine.
> + Consequentially, the client must consider invalid the pointer to that
> + descriptor.
> +
> 5. Issue pending DMA requests and wait for callback notification
>
> The transactions in the pending queue can be activated by calling the

Applied to the docs tree, thanks.

jon