lkml.org 
[lkml]   [2008]   [Jan]   [31]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 1/4] dma: document dma_{un}map_{single|sg}_attrs() interface
On Thu, Jan 31, 2008 at 03:38:48PM -0700, Grant Grundler wrote:

Thanks for looking through this.

I'll send an updated patchset that addresses your comments
as soon as I can - probably around Monday.

> ...
> > +struct dma_attrs encapsulates a set of "dma attributes". For the
> > +definition of struct dma_attrs see linux/dma-attrs.h.
>
> Because all architectures will share the set of attrs definitions,
> would it be reasonable to document the intent of each attr?
>
> Two reasons for doing this:
> 1) people reading the driver code should understand WHY the dma attr was added.
> 2) other arch maintainers need to know in order to implement the same attr
> for their shiny new toys.
>
>
> > +The interpretation of dma attributes is architecture-specific.
>
> This statement is really important....but:
> Could we add a reference to arch documentation for each attr?
>
> ie something public (doesn't have to be in linux source tree)
> which explains the subtlies of how that DMA attr actually works.
>
> Having worked on HP chipsets for 10+ years, I know releasing
> original HW docs is often not possible. I'm not asking for the
> impossible. Please don't flame me for that. But if the company
> is willing to publish the existance of a feature, a paragraph or
> two would be good marketing too. Maybe just include comments in
> the arch/ code that implements the feature and reference those
> comments in DMA-API.txt.
> ....

OK, I can certainly add an explanation of the attribute that
I'm worried about.

I think there's a reference to this behavior in our driver
porting guide - I can add a pointer to that, too.

This might also address your point above about documenting
each attribute - let me know once the next patch is out.

--
Arthur



\
 
 \ /
  Last update: 2008-02-01 04:11    [W:2.427 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site