Patch "drm/omap: fix tiled buffer stride calculations" has been added to the 4.4-stable tree

Patch "drm/omap: fix tiled buffer stride calculations" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    drm/omap: fix tiled buffer stride calculations

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-omap-fix-tiled-buffer-stride-calculations.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Apr 10 10:31:53 CEST 2018
From: Tomi Valkeinen <tomi.valkeinen@ti.com>
Date: Thu, 18 May 2017 11:51:51 +0300
Subject: drm/omap: fix tiled buffer stride calculations

From: Tomi Valkeinen <tomi.valkeinen@ti.com>


[ Upstream commit cc8dd7661ccc2d8dc88921da8e6cc7c2fcdb0341 ]

omap_gem uses page alignment for buffer stride. The related calculations
are a bit off, though, as byte stride of 4096 gets aligned to 8192,
instead of 4096.

This patch changes the code to use DIV_ROUND_UP(), which fixes those
calculations and makes them more readable.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/gpu/drm/omapdrm/omap_gem.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -158,7 +158,7 @@ static void evict_entry(struct drm_gem_o
 	size_t size = PAGE_SIZE * n;
 	loff_t off = mmap_offset(obj) +
 			(entry->obj_pgoff << PAGE_SHIFT);
-	const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
+	const int m = DIV_ROUND_UP(omap_obj->width << fmt, PAGE_SIZE);
 
 	if (m > 1) {
 		int i;
@@ -415,7 +415,7 @@ static int fault_2d(struct drm_gem_objec
 	 * into account in some of the math, so figure out virtual stride
 	 * in pages
 	 */
-	const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
+	const int m = DIV_ROUND_UP(omap_obj->width << fmt, PAGE_SIZE);
 
 	/* We don't use vmf->pgoff since that has the fake offset: */
 	pgoff = ((unsigned long)vmf->virtual_address -


Patches currently in stable-queue which might be from tomi.valkeinen@ti.com are

queue-4.4/drm-omap-fix-tiled-buffer-stride-calculations.patch