[PATCH] drm, i915: Fix pointer size cast

[Borislav Petkov <bp@alien8.de>]

From: Borislav Petkov <bp@suse.de>

gcc complains on 32-bit like this:

  drivers/gpu/drm/i915/intel_display.c: In function ‘intel_plane_obj_offset’:
  drivers/gpu/drm/i915/intel_display.c:2954:11: warning: cast to pointer from \
	  integer of different size [-Wint-to-pointer-cast]
    offset = (unsigned char *)vma->node.start;
             ^

because vma->node.start is u64 but a pointer on 32-bit is 4 bytes.

Do the calculations with an unsigned long directly and save us the
casts.

Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Cc: intel-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Borislav Petkov <bp@suse.de>
---
 drivers/gpu/drm/i915/intel_display.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 62211abe4922..640cb7c9b7f3 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -2941,7 +2941,7 @@ unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
 {
 	const struct i915_ggtt_view *view = &i915_ggtt_view_normal;
 	struct i915_vma *vma;
-	unsigned char *offset;
+	unsigned long offset;
 
 	if (intel_rotation_90_or_270(intel_plane->base.state->rotation))
 		view = &i915_ggtt_view_rotated;
@@ -2951,14 +2951,14 @@ unsigned long intel_plane_obj_offset(struct intel_plane *intel_plane,
 		view->type))
 		return -1;
 
-	offset = (unsigned char *)vma->node.start;
+	offset = vma->node.start;
 
 	if (plane == 1) {
 		offset += vma->ggtt_view.rotation_info.uv_start_page *
 			  PAGE_SIZE;
 	}
 
-	return (unsigned long)offset;
+	return offset;
 }
 
 static void skl_detach_scaler(struct intel_crtc *intel_crtc, int id)
-- 
2.3.5