From: Ilija Hadzic Date: Thu, 2 Feb 2012 15:26:24 +0000 (-0500) Subject: drm/radeon/kms/blit: fix blit copy for very large buffers X-Git-Tag: v3.3-rc3~33^2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=52b53a0bf8026a322cfa6cfec6a10dd31fef8752;p=pandora-kernel.git drm/radeon/kms/blit: fix blit copy for very large buffers Evergreen and NI blit copy was broken if the buffer maps to a rectangle whose one dimension is 16384 (max dimension allowed by these chips). In the mainline kernel, the problem is exposed only when buffers are very large (1G), but it's still a problem. The problem could be exposed for smaller buffers if anyone modifies the algorithm for rectangle construction in r600_blit_create_rect() (the reason why someone would modify that algorithm is to tune the performance of buffer moves). The root cause was in i2f() function which only operated on range between 0 and 16383. Fix this by extending the range of i2f() function to 0 to 32767. While at it improve the function so that the range can be easily extended in the future (if it becomes necessary), cleanup lines over 80 characters, and replace in-line comments with one strategic comment that explains the crux of the function. Credits to michel@daenzer.net for pointing out the root cause of the bug. v2: Fix I2F_MAX_INPUT constant definition goof and warn only once if input argument is out of range. Edit the comment a little bit to avoid some linguistic confusion and make it look better in general. Signed-off-by: Ilija Hadzic Reviewed-by: Alex Deucher Reviewed-by: Michel Dänzer Signed-off-by: Dave Airlie --- Reading git-diff-tree failed