diff mbox

[03/40] drm/rockchip: Respect page offset for PRIME mmap calls

Message ID 20180115171614.14474-4-thierry.escande@collabora.com (mailing list archive)
State New, archived
Headers show

Commit Message

Thierry Escande Jan. 15, 2018, 5:15 p.m. UTC
From: Ørjan Eide <orjan.eide@arm.com>

When mapping external DMA-bufs through the PRIME mmap call, we might be
given an offset which has to be respected. However for the internal DRM
GEM mmap path, we have to ignore the fake mmap offset used to identify
the buffer only. Currently the code always zeroes out vma->vm_pgoff,
which breaks the former.

This patch fixes the problem by moving the vm_pgoff assignment to a
function that is used only for GEM mmap path, so that the PRIME path
retains the original offset.

Cc: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Ørjan Eide <orjan.eide@arm.com>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
---
 drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Comments

Heiko Stübner Jan. 22, 2018, 10:44 a.m. UTC | #1
Am Montag, 15. Januar 2018, 18:15:37 CET schrieb Thierry Escande:
> From: Ørjan Eide <orjan.eide@arm.com>
> 
> When mapping external DMA-bufs through the PRIME mmap call, we might be
> given an offset which has to be respected. However for the internal DRM
> GEM mmap path, we have to ignore the fake mmap offset used to identify
> the buffer only. Currently the code always zeroes out vma->vm_pgoff,
> which breaks the former.
> 
> This patch fixes the problem by moving the vm_pgoff assignment to a
> function that is used only for GEM mmap path, so that the PRIME path
> retains the original offset.
> 
> Cc: Daniel Kurtz <djkurtz@chromium.org>
> Signed-off-by: Ørjan Eide <orjan.eide@arm.com>
> Signed-off-by: Tomasz Figa <tfiga@chromium.org>
> Signed-off-by: Sean Paul <seanpaul@chromium.org>
> Signed-off-by: Thierry Escande <thierry.escande@collabora.com>

On rk3036 + lima and rk3328 + lima
Tested-by: Heiko Stuebner <heiko@sntech.de>
diff mbox

Patch

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 5d52020deca1..074db7a92809 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -264,7 +264,6 @@  static int rockchip_drm_gem_object_mmap(struct drm_gem_object *obj,
 	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
 	 */
 	vma->vm_flags &= ~VM_PFNMAP;
-	vma->vm_pgoff = 0;
 
 	if (rk_obj->pages)
 		ret = rockchip_drm_gem_object_mmap_iommu(obj, vma);
@@ -299,6 +298,12 @@  int rockchip_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 	if (ret)
 		return ret;
 
+	/*
+	 * 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 = vma->vm_private_data;
 
 	return rockchip_drm_gem_object_mmap(obj, vma);