Re: [PATCH 2.6.20 1/1] fbdev,mm: hecuba/E-Ink fbdev driver

Jaya Kumar
2007-02-17T13:25:10Z

On 2/17/07, Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> On Sat, 2007-02-17 at 11:42 +0100, Jaya Kumar wrote:
> > Hi James, Geert, lkml and mm,
>
> Hi Jaya,
>
> > This patch adds support for the Hecuba/E-Ink display with deferred IO.
> > The changes from the previous version are to switch to using a mutex
> > and lock_page. I welcome your feedback and advice.
>
> This changelog ought to be a little more extensive; esp. because you're
> using these fancy new functions ->page_mkwrite() and page_mkclean() in a
> novel way.

Hi Peter,

I had put the comment explaining the usage of mkwrite/mkclean in the
.c file. Oh, I see, in the changelog message. Ok, I'll update with a
changelog message mentioning mkwrite/mkclean.

>
> Also, I'd still like to see a way to call msync() on the mmap'ed region
> to force a flush. I think providing a fb_fsync() method in fbmem.c and a
> hook down to the driver ought to work.

I'm hoping fbdev folk will give feedback if this is okay. James,
Geert, what do you think?

>
> Also, you now seem to use a fixed 1 second delay, perhaps provide an
> ioctl or something to customize this?

Ok. Will do.

>
> And, as Andrew suggested last time around, could you perhaps push this
> fancy new idea into the FB layer so that more drivers can make us of it?

I would like to do that very much. I have some ideas how it could work
for devices that support clean partial updates by tracking touched
pages. But I wonder if it is too early to try to abstract this out.
James, Geert, what do you think?

Thanks,
jaya