Hi, Sascha Hauer. thank you for your comments and below is my answer. Sascha Hauer wrote: > Hi, > > On Fri, Jul 29, 2011 at 04:24:35PM +0900, Inki Dae wrote: >> This patch is a DRM Driver(only including FIMD Driver yet) >> for Samsung SoC Exynos4210. and as RFC, I am sending only DRM driver part. >> >> this patch is based on git repository below: >> git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6.git, >> branch: drm-next >> commit-id: 5a96a899bbdee86024ab9ea6d02b9e242faacbed >> >> We tried to re-use lowlevel codes of the FIMD driver(s3c-fb.c >> based on Linux framebuffer) but couldn't so because lowlevel codes >> of s3c-fb.c are included internally and so this driver shares only >> platform device. >> >> Sub drivers such as fimd or hdmi have indenpendent platform device and >> Platform driver and when driver's probe is called, the driver object >> including callbacks(for hardware control) would be registered to >> Samsung drm driver. and then when samsung drm driver is probed, >> each probe callback of the driver object registered is called so that >> additional callbacks for drm framework would be set at this time. >> >> We used GEM framework for buffer management and this driver supports >> only physically continuous memory yet(non-iommu). and for buffer allocation, >> we used DMA APIs(dma_alloc_writecombine) but we will change it to CMA instead >> of DMA APIs later. >> >> Refer to this link for CMA(Continuous Memory Allocator): >> http://lkml.org/lkml/2011/7/20/45 >> >> Future works: >> - HDMI support. >> - drm plane feature support. >> refer to this link for drm plane feature: >> http://www.spinics.net/lists/dri-devel/msg11778.html >> - change the allocator to CMA. >> - iommu support.(for non-continuous physical memory usage) >> - fimd driver update. >> - add exception codes and code clean. >> >> to support all features above, we need long time and hard work. >> so we wish that only some features(fimd and non-iommu) are applied to >> mainline first. >> >> We would be pleased you to give us your comments. > > So far I only had a quick look over the driver. You might know that > I wrote a Freescale i.MX drm driver which I posted to the list some time > ago. > > My driver lacks GEM support which your driver has, so I specifically > looked at this part. It seems we could reuse the GEM code on i.MX and > probably on most other ARMs aswell. Can you split out this code > and remove the samsung_ namespace? > By any chance, you mean drm_gem_free_mmap_offset()? this patch had already been posted by Rob Clark, Omap TI as RFC.
you can refer to this link for it. http://www.spinics.net/lists/dri-devel/msg13018.html if so, I am aware of it but his patch isn't applied to drm-next yet and so my drm driver doesn't include his patch. of course I will reuse it and remove the samsung_ namespace as you pointed out if the patch is applied to drm-next. > btw you should probably Cc the arm Linux Kernel mailing list as this > is the list where your users are. > > I look forward to have the first ARM drm drivers mainline, so I really > appreciate your work :) > > Sascha > Thank you for your comments and advice again. :)
