Re: [PATCH 08/10] drm/exynos: initialize DMA ops for virtual Exynos DRM device

[Inki Dae <inki.dae@samsung.com>]

Hi Marek,

2016년 02월 03일 21:42에 Marek Szyprowski 이(가) 쓴 글:
> Virtual DRM device is used for memory allocation for GEM objects. On
> some architectures null dma operations are assigned for virtual devices
> if no explicit initialization has been made.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/gpu/drm/exynos/exynos_drm_drv.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> index 68f0f36..a33ea44 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
> @@ -144,6 +144,7 @@ static int exynos_drm_load(struct drm_device *dev, unsigned long flags)
>  	init_waitqueue_head(&private->wait);
>  	spin_lock_init(&private->lock);
>  
> +	arch_setup_dma_ops(dev->dev, 0, DMA_BIT_MASK(32), false, false);

As you got the report, above function incurrs build error below,
ERROR: "arch_setup_dma_ops" [drivers/gpu/drm/exynos/exynosdrm.ko] undefined!

Exynos drm can be built as a module. In this case, arch_setup_dma_ops cannot be accessed by the module.

I could fix it easily like below but I'm not sure that it's reasonable.

+extern void arch_setup_dma_ops(struct device *dev, u64 dma_base,
+                                     u64 size, struct iommu_ops *iommu,
+                                     bool coherent) { };

Thanks,
Inki Dae

>  	dev_set_drvdata(dev->dev, dev);
>  	dev->dev_private = (void *)private;
>  
>