On 2014?09?22? 22:43, Arnd Bergmann wrote: > On Monday 22 September 2014 18:48:54 Mark yao wrote: >> diff --git a/drivers/gpu/drm/rockchip/Kconfig b/drivers/gpu/drm/rockchip/Kconfig >> new file mode 100644 >> index 0000000..7146c80 >> --- /dev/null >> +++ b/drivers/gpu/drm/rockchip/Kconfig >> @@ -0,0 +1,19 @@ >> +config DRM_ROCKCHIP >> + tristate "DRM Support for Rockchip" >> + depends on DRM && ROCKCHIP_IOMMU >> + select ARM_DMA_USE_IOMMU >> + select IOMMU_API >> + select DRM_KMS_HELPER >> + select DRM_KMS_FB_HELPER >> + select DRM_PANEL >> + select FB_CFB_FILLRECT >> + select FB_CFB_COPYAREA >> + select FB_CFB_IMAGEBLIT >> + select VT_HW_CONSOLE_BINDING if FRAMEBUFFER_CONSOLE >> + select VIDEOMODE_HELPERS > Be careful with 'select', at least some of these should be 'depends on'. > In particular IOMMU_API and ARM_DMA_USE_IOMMU, but possibly others > as well. Just check how the symbols are used normally, if you get this > wrong, we can end up with incorrect dependencies or loops. > I see, I will change it. >> diff --git a/drivers/gpu/drm/rockchip/Makefile b/drivers/gpu/drm/rockchip/Makefile >> new file mode 100644 >> index 0000000..6e6d468 >> --- /dev/null >> +++ b/drivers/gpu/drm/rockchip/Makefile >> @@ -0,0 +1,10 @@ >> +# >> +# Makefile for the drm device driver. This driver provides support for the >> +# Direct Rendering Infrastructure (DRI) in XFree86 4.1.0 and higher. >> + >> +ccflags-y := -Iinclude/drm -Idrivers/gpu/drm/rockchip > The second one should not be required. Sure, I will change it. >> +static int rockchip_drm_load(struct drm_device *drm_dev, unsigned long flags) >> +{ >> + struct rockchip_drm_private *private; >> + struct dma_iommu_mapping *mapping; >> + struct device *dev = drm_dev->dev; >> + int ret; >> + >> + private = devm_kzalloc(drm_dev->dev, sizeof(*private), GFP_KERNEL); >> + if (!private) >> + return -ENOMEM; >> + >> + dev_set_drvdata(drm_dev->dev, dev); >> + drm_dev->dev_private = private; >> + >> + drm_mode_config_init(drm_dev); >> + >> + rockchip_drm_mode_config_init(drm_dev); >> + >> + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms), >> + GFP_KERNEL); >> + if (!dev->dma_parms) { >> + ret = -ENOMEM; >> + goto err_config_cleanup; >> + } >> + >> + /* TODO(djkurtz): fetch the mapping start/size from somewhere */ >> + mapping = arm_iommu_create_mapping(&platform_bus_type, 0x10000000, >> + SZ_1G); >> + if (IS_ERR(mapping)) { >> + ret = PTR_ERR(mapping); >> + goto err_config_cleanup; >> + } >> + >> + dma_set_coherent_mask(dev, DMA_BIT_MASK(32)); > This is the default coherent mask. If you call this function, you > should normally check the return value, or call dma_set_mask first, > which you apparently don't do here, and in another place in this > patch. > > Arnd > > >