fb_do_apertures_overlap is returning wrong value when one aperture
is completely whithin the other. Add generic ranges_overlap macro
(probably kernel.h candidate) and use it here.
Signed-off-by: Marcin Slusarz <marcin.slus...@gmail.com>
Cc: Dave Airlie <airl...@redhat.com>
Cc: Peter Jones <pjo...@redhat.com>
Cc: Andrew Morton <a...@linux-foundation.org>
---
drivers/video/fbmem.c | 24 +++++++++++++++++-------
1 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index a15b44e..41f2e5e 100644
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1468,15 +1468,25 @@ static int fb_check_foreignness(struct fb_info *fi)
return 0;
}
+/**
+ * ranges_overlap - check whether two ranges overlap (their intersection is
not empty)
+ * @start1: start of the first range
+ * @size1: length of the first range
+ * @start2: start of the second range
+ * @size2: length of the second range
+ */
+#define ranges_overlap(start1, size1, start2, size2) ({ \
+ typeof(start1) __start1 = (start1); \
+ typeof(size1) __size1 = (size1); \
+ typeof(start2) __start2 = (start2); \
+ typeof(size2) __size2 = (size2); \
+ __start1 < __start2 + __size2 && __start1 + __size1 > __start2; \
+})
+
static bool fb_do_apertures_overlap(struct fb_info *gen, struct fb_info *hw)
{
- /* is the generic aperture base the same as the HW one */
- if (gen->aperture_base == hw->aperture_base)
- return true;
- /* is the generic aperture base inside the hw base->hw base+size */
- if (gen->aperture_base > hw->aperture_base && gen->aperture_base <=
hw->aperture_base + hw->aperture_size)
- return true;
- return false;
+ return ranges_overlap(gen->aperture_base, gen->aperture_size,
+ hw->aperture_base, hw->aperture_size);
}
/**
* register_framebuffer - registers a frame buffer device
--
1.7.0.4
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