[PATCH v14 0/3] Add drm driver for Rockchip Socs

[Heiko Stübner]

Am Donnerstag, 27. November 2014, 14:05:00 schrieb Daniel Kurtz:
> On Thu, Nov 27, 2014 at 2:08 AM, Mark yao <mark.yao at rock-chips.com> wrote:
> > On 2014年11月27日 10:12, Dave Airlie wrote:
> >>> Hi Dave
> >>> 
> >>>      Do you mean that I need send you a branch, based on drm-next, merge
> >>>      with
> >>> 
> >>> iommu tree and rockchip drm?
> >> 
> >> Yes, grab drm-next, git pull the arm/rockchip branch from Joerg's
> >> tree, put rockchip drm
> >> patches on top, send me pull request.
> >> 
> >> I'll validate it then.
> >> 
> >> Dave.
> > 
> > Hi Dave
> > 
> >     I have send a pull request to you, with Joerg's iommu arm/rockchip
> >     branch.
> >     
> >     I got a same problem when use "make multi_v7_defconfig" as Heiko said:
> >         drivers/video/fbdev/Kconfig:5:error: recursive dependency
> >         detected!
> >         drivers/video/fbdev/Kconfig:5:    symbol FB is selected by
> >         DRM_KMS_FB_HELPER drivers/gpu/drm/Kconfig:34:    symbol
> >         DRM_KMS_FB_HELPER is selected by DRM_ROCKCHIP
> >         drivers/gpu/drm/rockchip/Kconfig:1:    symbol DRM_ROCKCHIP
> >         depends on ARM_DMA_USE_IOMMU arch/arm/Kconfig:95:    symbol
> >         ARM_DMA_USE_IOMMU is selected by VIDEO_OMAP3
> >         drivers/media/platform/Kconfig:96:    symbol VIDEO_OMAP3 depends
> >         on VIDEO_V4L2 drivers/media/v4l2-core/Kconfig:6:    symbol
> >         VIDEO_V4L2 depends on I2C drivers/i2c/Kconfig:7:    symbol I2C is
> >         selected by FB_DDC
> >         drivers/video/fbdev/Kconfig:59:    symbol FB_DDC is selected by
> >         FB_CYBER2000_DDC drivers/video/fbdev/Kconfig:374:    symbol
> >         FB_CYBER2000_DDC depends on FB_CYBER2000
> >         drivers/video/fbdev/Kconfig:362:    symbol FB_CYBER2000 depends
> >         on FB>     
> >     I was confused how to solve the recursive dependency, remove depends
> >     on ARM_DMA_USE_IOMMU & IOMMU_API?
> The "depends on ARM_DMA_USE_IOMMU & IOMMU_API" was suggested by Arnd
> Bergmann during code review (originally they were selected).
> 
> Removing them definitely fixes the dependency recursion.
> Also, since they are both already selected by ROCKCHIP_IOMMU,
> everything will build correctly.
> So, this sounds good to me, but I am no expert on Kconfig.

personally I'd think the omap v4l stuff is at fault here. It is selecting 
ARM_DMA_USE_IOMMU and OMAP_IOMMU instead of depending on them.

And OMAP_IOMMU is a regular driver option which can be selected through 
Kconfig, so I don't think it should get selected but enabled by choice.

It would be interesting to know if the Exynos drm is also affected by this, as 
it is using a similar depency-structure by depending on the iommu and 
ARM_DMA_USE_IOMMU.


Heiko