On Wed, Feb 9, 2011 at 7:12 AM, Alex Deucher alexdeucher@gmail.com wrote:
On Tue, Feb 8, 2011 at 5:47 PM, Andy Walls awalls@md.metrocast.net wrote:
On Tue, 2011-02-08 at 10:28 -0500, Alex Deucher wrote:
On Tue, Feb 8, 2011 at 4:47 AM, Hans Verkuil hansverk@cisco.com wrote:
Just two quick notes. I'll try to do a full review this weekend.
On Tuesday, February 08, 2011 10:30:22 Tomasz Stanislawski wrote:
============== Introduction ==============
The purpose of this RFC is to discuss the driver for a TV output interface available in upcoming Samsung SoC. The HW is able to generate digital and analog signals. Current version of the driver supports only digital output.
Internally the driver uses videobuf2 framework, and CMA memory allocator.
Not
all of them are merged by now, but I decided to post the sources to start discussion driver's design.
Cisco (i.e. a few colleagues and myself) are working on this. We hope to post an RFC by the end of this month. We also have a proposal for CEC support in the pipeline.
Any reason to not use the drm kms APIs for modesetting, display configuration, and hotplug support? We already have the infrastructure in place for complex display configurations and generating events for hotplug interrupts. It would seem to make more sense to me to fix any deficiencies in the KMS APIs than to spin a new API. Things like CEC would be a natural fit since a lot of desktop GPUs support hdmi audio/3d/etc. and are already using kms.
Alex
I'll toss one out: lack of API documentation for driver or application developers to use.
When I last looked at converting ivtvfb to use DRM, KMS, TTM, etc. (to possibly get rid of reliance on the ivtv X video driver http://dl.ivtvdriver.org/xf86-video-ivtv/ ), I found the documentation was really sparse.
DRM had the most documentation under Documentation/DocBook/drm.tmpl, but the userland API wasn't fleshed out. GEM was talked about a bit in there as well, IIRC.
TTM documentation was essentially non-existant.
I can't find any KMS documentation either.
I recall having to read much of the drm code, and having to look at the radeon driver, just to tease out what the DRM ioctls needed to do.
Am I missing a Documentation source for the APIs?
Yes,
My summer of code project's purpose was to create something of a tutorial for writing a KMS driver. The code, split out into something like 15 step-by-step patches, and accompanying documentation are available from Google's website.
http://code.google.com/p/google-summer-of-code-2010-xorg/downloads/detail?na...
My repository (doesn't include the documentation) is available here: http://git.kernel.org/?p=linux/kernel/git/mattst88/glint.git;a=summary
There's a 'rebased' branch that contains API changes required for the code to work with 2.6.37~.
I hope it's useful to you.
I can't image how the lack of documentation of an used and tested API could be a serious reason to write you own. That makes absolutely no sense to me, so I hope you'll decide to use KMS.
Matt