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[v3] video: Versatile Express DVI output driver

Message ID 1353333377.3303.7.camel@hornet
State New
Headers show

Pull-request

git://git.linaro.org/people/pawelmoll/linux.git vexpress-drivers2

Message

Pawel Moll Nov. 19, 2012, 1:56 p.m. UTC 
Hi Arnd, Olof,

One of the important parts of the VE update is the display muxer
driver...

On Tue, 2012-10-30 at 15:58 +0000, Pawel Moll wrote:
> Hello again Florian,
> 
> On Tue, 2012-10-16 at 17:30 +0100, Pawel Moll wrote:
> > Versatile Express' DVI video output can be connected to one the three
> > sources - motherboard's CLCD controller or a video signal generated
> > by one of the daughterboards.
> > 
> > This driver configures the muxer FPGA so the output displays content
> > of one of the framebuffers in the system (0 by default, can be changed
> > by user writing to the "fb" sysfs attribute of the muxfpga device).
> > 
> > It will also set up the display formatter mode and keep it up
> > to date with mode changes requested by the user (eg. with fbset
> > tool).
> > 
> > Signed-off-by: Pawel Moll <pawel.moll@arm.com>
> 
> It's just a polite a friendly nag regarding this patch - it's been 2
> weeks since I posted this version (and 1.5 month since the first one)...
> 
> Does it look good enough or completely wrong?

I've asked the framebuffer people 3 times about this but got no comment
whatsoever:

https://patchwork.kernel.org/patch/1473091/
https://patchwork.kernel.org/patch/1601781/

so I assume there is no problem with merging this code ;-) Therefore,
would you be so kind to pull this single patch? Without it the 3.8
kernel will not be able to show anything on VE's display...

The following changes since commit f4a75d2eb7b1e2206094b901be09adb31ba63681:

  Linux 3.7-rc6 (2012-11-16 17:42:40 -0800)

are available in the git repository at:

  git://git.linaro.org/people/pawelmoll/linux.git vexpress-drivers2

for you to fetch changes up to 357e174056d44c6614afec6c5ace1c2aea2ef0bb:

  video: Versatile Express DVI output driver (2012-11-19 11:12:40 +0000)

This is the very last thing for 3.8 merge window from me.

Thanks and regards

Paweł

Comments

Arnd Bergmann Nov. 19, 2012, 3:43 p.m. UTC | #1 
On Monday 19 November 2012, Pawel Moll wrote:
> I've asked the framebuffer people 3 times about this but got no comment
> whatsoever:
> 
> https://patchwork.kernel.org/patch/1473091/
> https://patchwork.kernel.org/patch/1601781/
> 
> so I assume there is no problem with merging this code ;-) Therefore,
> would you be so kind to pull this single patch? Without it the 3.8
> kernel will not be able to show anything on VE's display...

Hi Pawel,

I have two comments for the patch that need to be fixed:

* vexpress_dvi_fb_select uses the 'fb' argument as an index into
  the registered_fb array, but does not check for overflow against
  FB_MAX. I think you need to use get_fb_info().

* There is no documentation for the newly introduced sysfs interface.

	Arnd
Pawel Moll Nov. 19, 2012, 4:26 p.m. UTC | #2 
On Mon, 2012-11-19 at 15:43 +0000, Arnd Bergmann wrote:
> * vexpress_dvi_fb_select uses the 'fb' argument as an index into
>   the registered_fb array, but does not check for overflow against
>   FB_MAX. 

Uh, right. Will fix in a second.

> I think you need to use get_fb_info().

I was considering this, but it's a static. And I don't want to change
the fb core, as I'm planning to plug this driver into the "Generic
Panel/Display Framework" [1] that Laurent is working on when it's
available. Then I won't have to hack into the core at all...

[1] http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/52565

> * There is no documentation for the newly introduced sysfs interface.

Hm, I didn't want to do that, as it's currently just a debug feature -
there is no class symlink to the device available
(Documentation/ABI/testing/sysfs-devices) so there's no universal way of
describing the path to the device.

I'll do my best and post v4 soon.

Paweł
Pawel Moll Dec. 12, 2012, 6:05 p.m. UTC | #3 
Hi Arnd,

On Mon, 2012-11-19 at 16:39 +0000, Pawel Moll wrote:
> Versatile Express' DVI video output can be connected to one the three
> sources - motherboard's CLCD controller or a video signal generated
> by one of the daughterboards.
> 
> This driver configures the muxer FPGA so the output displays content
> of one of the framebuffers in the system (0 by default, can be changed
> by user writing to the "fb" sysfs attribute of the muxfpga device).
> 
> It will also set up the display formatter mode and keep it up
> to date with mode changes requested by the user (eg. with fbset
> tool).
> 
> Signed-off-by: Pawel Moll <pawel.moll@arm.com>

Could I just politely remind about this one?

Paweł