On Die, 2011-08-09 at 23:52 +0530, Mayank Rungta wrote:
Added a check for the radeon ring buffer write index in r600.c which reads 0xffffffff on resume. This results in an Oops during radeon_ring_write. Masking the value averts this.
This problem is not seen to be fixed in 3.0 r600.c as well.
Detailed analysis of the problem can be found at -
https://bugs.launchpad.net/ubuntu/+source/linux/+bug/820746/
BUG: unable to handle kernel paging request at fa501ffc - Oops at r600_cp_start+0x48/0x380 in r600_cp_resume+0x345/0x580 [radeon]
drivers/gpu/drm/radeon/r600.c
--- linux-2.6.38/drivers/gpu/drm/radeon/r600.c.orig 2011-08-05 15:39:40.824612700 +0530 +++ linux-2.6.38/drivers/gpu/drm/radeon/r600.c 2011-08-08 05:29:21.744417857 +0530 @@ -2218,6 +2218,8 @@ int r600_cp_resume(struct radeon_device
rdev->cp.rptr = RREG32(CP_RB_RPTR); rdev->cp.wptr = RREG32(CP_RB_WPTR);
- /* protect against crazy HW on resume */
- rdev->cp.wptr &= rdev->cp.ptr_mask;
The indentation of the lines you're adding doesn't match the surrounding lines.
Although the same workaround is already in r100.c, I wonder if we shouldn't rather try and eliminate all reads from the CP_RB_WPTR register, at least other than for debugging purposes. Alex, what do you think?
Otherwise, this should probably be added in evergreen.c as well.
Developer's Certificate of Origin 1.1 [...]
No need to include all this text, just the *-by: tags are enough.