From: Daniel Haid Date: Wed, 8 Jun 2011 10:04:45 +0000 (+1000) Subject: drm/radeon/kms: fix for radeon on systems >4GB without hardware iommu X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=62fff811d73095bd95579d72f558f03c78f7914a;p=openwrt%2Fstaging%2Fblogic.git drm/radeon/kms: fix for radeon on systems >4GB without hardware iommu On my x86_64 system with >4GB of ram and swiotlb instead of a hardware iommu (because I have a VIA chipset), the call to pci_set_dma_mask (see below) with 40bits returns an error. But it seems that the radeon driver is designed to have need_dma32 = true exactly if pci_set_dma_mask is called with 32 bits and false if it is called with 40 bits. I have read somewhere that the default are 32 bits. So if the call fails I suppose that need_dma32 should be set to true. And indeed the patch fixes the problem I have had before and which I had described here: http://choon.net/forum/read.php?21,106131,115940 Acked-by: Alex Deucher cc: stable@kernel.org Signed-off-by: Dave Airlie --- diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c index d77ede3e67ce..e680501c78ea 100644 --- a/drivers/gpu/drm/radeon/radeon_device.c +++ b/drivers/gpu/drm/radeon/radeon_device.c @@ -754,6 +754,7 @@ int radeon_device_init(struct radeon_device *rdev, dma_bits = rdev->need_dma32 ? 32 : 40; r = pci_set_dma_mask(rdev->pdev, DMA_BIT_MASK(dma_bits)); if (r) { + rdev->need_dma32 = true; printk(KERN_WARNING "radeon: No suitable DMA available.\n"); }