Re: [PATCH 1/2] drm: rockchip: Don't pass DRM fake offset to dma-api

From: Mark yao
Date: Mon Apr 20 2015 - 01:44:42 EST


On 2015å04æ20æ 13:34, Mark yao wrote:
On 2015å04æ19æ 00:55, Heiko StÃbner wrote:
Am Donnerstag, 16. April 2015, 16:41:51 schrieb Ãrjan Eide:
Set vm_pgoff to 0 after using it to look up the GEM node, before passing
it on rockchip_gem_mmap_buf() where the offset must be from the start of
the buffer.

Passing in the fake offset currently works because the
dma_mmap_attrs implementation that is used for this device,
arm_iommu_mmap_attrs, ignores the offset completely.

Signed-off-by: Ãrjan Eide <orjan.eide@xxxxxxx>
both patches on a rk3288-veyron-pinky

Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>

Through which tree do you want to take these patches? I guess the rockchip-drm
related patch should go through the tree that will take the dma-mapping patch,
so you'll probably need an "Ack" from Mark Yao (Cc'ed).


Heiko

---
drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c index 7ca8799e..69f01c3
100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -94,6 +94,11 @@ int rockchip_gem_mmap(struct file *filp, struct
vm_area_struct *vma) return -EACCES;
}

+ /* Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
+ * whole buffer from the start.
+ */
+ vma->vm_pgoff = 0;
+
obj = container_of(node, struct drm_gem_object, vma_node);
ret = rockchip_gem_mmap_buf(obj, vma);



Thanks for this fix,
Acked-by: Mark Yao <mark.yao@xxxxxxxxxxxxxx>

I met this problem when work with gem non-iommu path, set vma->vm_pgoff = 0 solved it. :-)

--
ïark

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