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

From: Jaya Kumar
Date: Sat Feb 17 2007 - 08:25:40 EST

On 2/17/07, Peter Zijlstra <a.p.zijlstra@xxxxxxxxx> 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?

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