I'm still in the learning-as-I-go phase here, so definitely not ready to propose a solution, but it does seem to me like there is room for some sort of kms-helper library here to handle more of the boilerplate xf86-video-* stuff.. I guess I'll have a better picture once I have a chance to add support for the various multi-monitor configurations. But certainly would be interested if anyone already has some ideas.
I have been thinking about this as well. One of the short coming for DRM on embedded platforms is the lack of a small well defined library that one could use. Right now libkms only handles buffer allocation. The mode setting is currently tied to the libdrm library. It would be nice to seperate the two out more. Move the mode setting code to libkms and then have libdrm be a wrapper around this. This way libdrm can both support the legacy drm drivers and the new kms drivers at the same time. It also makes a clear seperation. Jakob if you are willing to take this work I will gladly seen you patches.
To accommodate the fact of independent display controller and GPU components in ARM SOC, it will be better if we can separate KMS from DRM both in kernel space and user space (i.e, create a new drivers/video/kms directory for kernel side, move KMS related code in libdrm to libkms in user space). Then we can build xrandr1.2+ support based on KMS for ARM platforms, even if DRM is still not supported. Besides, for buffer management part (GEM) in DRM, if possible, we can also make it an independent module leaving DRM just a wrapper, so that the GEM stuff can be used more flexibly.
Regards, Jammy
On Fri, Feb 18, 2011 at 12:14 AM, James Simmons jsimmons@infradead.orgwrote:
I'm still in the learning-as-I-go phase here, so definitely not ready to propose a solution, but it does seem to me like there is room for some sort of kms-helper library here to handle more of the boilerplate xf86-video-* stuff.. I guess I'll have a better picture once I have a chance to add support for the various multi-monitor configurations. But certainly would be interested if anyone already has some ideas.
I have been thinking about this as well. One of the short coming for DRM on embedded platforms is the lack of a small well defined library that one could use. Right now libkms only handles buffer allocation. The mode setting is currently tied to the libdrm library. It would be nice to seperate the two out more. Move the mode setting code to libkms and then have libdrm be a wrapper around this. This way libdrm can both support the legacy drm drivers and the new kms drivers at the same time. It also makes a clear seperation. Jakob if you are willing to take this work I will gladly seen you patches.
linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
I'm all for a more modular drm, although I think the framework of CRTCs, encoders, and connectors is a nice fit, at least for our hw. It would be nice to have a better way to expose overlays. And I'm still thinking about how/if GEM fits in with our various video and 2/3d accelerators.
BR, -R
On Thu, Feb 17, 2011 at 8:19 PM, Jammy Zhou jammy.zhou@linaro.org wrote:
To accommodate the fact of independent display controller and GPU components in ARM SOC, it will be better if we can separate KMS from DRM both in kernel space and user space (i.e, create a new drivers/video/kms directory for kernel side, move KMS related code in libdrm to libkms in user space). Then we can build xrandr1.2+ support based on KMS for ARM platforms, even if DRM is still not supported. Besides, for buffer management part (GEM) in DRM, if possible, we can also make it an independent module leaving DRM just a wrapper, so that the GEM stuff can be used more flexibly.
Regards, Jammy
On Fri, Feb 18, 2011 at 12:14 AM, James Simmons jsimmons@infradead.org wrote:
I'm still in the learning-as-I-go phase here, so definitely not ready to propose a solution, but it does seem to me like there is room for some sort of kms-helper library here to handle more of the boilerplate xf86-video-* stuff.. I guess I'll have a better picture once I have a chance to add support for the various multi-monitor configurations. But certainly would be interested if anyone already has some ideas.
I have been thinking about this as well. One of the short coming for DRM on embedded platforms is the lack of a small well defined library that one could use. Right now libkms only handles buffer allocation. The mode setting is currently tied to the libdrm library. It would be nice to seperate the two out more. Move the mode setting code to libkms and then have libdrm be a wrapper around this. This way libdrm can both support the legacy drm drivers and the new kms drivers at the same time. It also makes a clear seperation. Jakob if you are willing to take this work I will gladly seen you patches.
linaro-dev mailing list linaro-dev@lists.linaro.org http://lists.linaro.org/mailman/listinfo/linaro-dev
On Fri, Feb 18, 2011 at 2:14 AM, James Simmons jsimmons@infradead.org wrote:
I'm still in the learning-as-I-go phase here, so definitely not ready to propose a solution, but it does seem to me like there is room for some sort of kms-helper library here to handle more of the boilerplate xf86-video-* stuff.. I guess I'll have a better picture once I have a chance to add support for the various multi-monitor configurations. But certainly would be interested if anyone already has some ideas.
I have been thinking about this as well. One of the short coming for DRM on embedded platforms is the lack of a small well defined library that one could use. Right now libkms only handles buffer allocation. The mode setting is currently tied to the libdrm library. It would be nice to seperate the two out more. Move the mode setting code to libkms and then have libdrm be a wrapper around this. This way libdrm can both support the legacy drm drivers and the new kms drivers at the same time. It also makes a clear seperation. Jakob if you are willing to take this work I will gladly seen you patches.
the problem with that is libkms relies on libdrm, so you'd have a circular dependency.
With the addition of the dumb ioctl to the kernel we can certainly avoid some of that dependency, but you guys are missing one important point about libkms, its meant to be a fallback.
Why?
well because most GPUs in reality have non-generic memory layouts, they prefer having tiled buffers for different things and different types of tiling. There is simply no nice way to abstract that out, since it depends on the userspace libraries that use this. Starting off with an untiled allocation for the frontbuffer can pretty much leave you messed up when you plug anything like acceleration in afterwards.
I have been looking at this from the USB driver pov as well, and we can probably resurrect the old xf86-video-modesetting driver along with some code in the X server maybe, mesa also has a libkms fallback X driver that works quite well if just a bit messy to build (since its in mesa).
Dave.
dri-devel@lists.freedesktop.org
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Clark, Rob -
Dave Airlie -
James Simmons -
Jammy Zhou