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
>
>
>
