From: Dave Airlie <airlied@gmail.com>
Subject: [PATCH] drm/udl: avoid swiotlb for imported vmap buffers.
Date: Wed,  1 May 2013 14:30:44 +1000
Message-ID: <1367382644-30788-1-git-send-email-airlied@gmail.com>
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Sender: dri-devel-bounces+sf-dri-devel=m.gmane.org@lists.freedesktop.org
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To: dri-devel@lists.freedesktop.org

Since we ask the dmabuf owner to map the dma-buf into our device
address space, but for udl at present that is the CPU address space,
since we don't DMA directly from the mapped buffer.

However if we don't set a dma mask on the usb device, the mapping
ends up using swiotlb on machines that have it enabled, which
is less than desireable.

Signed-off-by: Dave Airlie <airlied@redhat.com>
---
 drivers/gpu/drm/udl/udl_main.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/udl/udl_main.c b/drivers/gpu/drm/udl/udl_main.c
index 0ce2d71..6770e1b 100644
--- a/drivers/gpu/drm/udl/udl_main.c
+++ b/drivers/gpu/drm/udl/udl_main.c
@@ -293,6 +293,7 @@ int udl_driver_load(struct drm_device *dev, unsigned long flags)
 	udl->ddev = dev;
 	dev->dev_private = udl;
 
+	dma_set_mask(dev->dev, DMA_BIT_MASK(64));
 	if (!udl_parse_vendor_descriptor(dev, dev->usbdev)) {
 		DRM_ERROR("firmware not recognized. Assume incompatible device\n");
 		goto err;
-- 
1.8.2