Hello,
This patchset resolves the issues with using 'exynos-drm' virtual device for allocating DMA buffers and performing various DMA-mapping operations inside Exynos DRM driver.
'exynos-drm' is a pure virtual device and some architectures (like ARM64) doesn't configure DMA-mapping operations for such devices. Also on ARM architecture some hacks were needed to setup IOMMU-based DMA-mapping ops for this virtual device to use common IO/DMA address space for all devices, which are a part of Exynos DRM subsystem.
Instead of configuring DMA-mapping ops for virtual device (like I initially proposed in this patch: http://www.spinics.net/lists/linux-samsung-soc/msg50699.html ), different device is is used by Exynos GEM code for DMA-mapping operations. In this approach, the real device of one of the CRTC devices is used for all DMA-mapping operations. This way all hacks related to configuring DMA-mapping ops for virtual device are avoided. This approach also works fine in case of Exynos DRM driver built as module. Patch no 2 implements this approach.
Patch no 1 is a simple refactoring of driver and device registeration procedure. It groups all pointers to the subdrivers in one array with additional flags, instead of having them in 3 separate arrays (with possible duplication). Implementing the main feature of this patchset without this refactoring would result in one more array with duplicated entries for all CRTC drivers.
Patches are based on the currect exynos-drm-next branch.
Best regards Marek Szyprowski Samsung R&D Institute Poland
Patch summary:
Marek Szyprowski (2): drm/exynos: refactor driver and device registration code drm/exynos: use real device for DMA-mapping operations
drivers/gpu/drm/exynos/exynos_drm_drv.c | 265 ++++++++++++++++-------------- drivers/gpu/drm/exynos/exynos_drm_drv.h | 9 +- drivers/gpu/drm/exynos/exynos_drm_fbdev.c | 2 +- drivers/gpu/drm/exynos/exynos_drm_g2d.c | 6 +- drivers/gpu/drm/exynos/exynos_drm_gem.c | 14 +- drivers/gpu/drm/exynos/exynos_drm_iommu.c | 37 +---- drivers/gpu/drm/exynos/exynos_drm_iommu.h | 5 +- 7 files changed, 169 insertions(+), 169 deletions(-)