glyph corruption on Radeon 3850HD bisected to drm/radeon: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR handling

glyph corruption on Radeon 3850HD bisected to drm/radeon: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR handling

[Arthur Marsh]

Hi, I experienced glyph corruption in iceweasel (unbranded Firefox) on a 
machine with a Radeon 3850HD video card and 4.1.0-rc4 and later kernels.

Git bisecting pointed to the commit 607d48063512707a414e346972e2210dc71ab491

http://git.kernel.org/linus/;a=commit;h=607d48063512707a414e346972e2210dc71ab491

drm/radeon: fix VM_CONTEXT*_PAGE_TABLE_END_ADDR handling

I'm happy to provide further information and run further tests to help 
identify the problem.

Arthur.

Selected dmesg output:

[    0.000000] Command line: BOOT_IMAGE=/vmlinuz-4.1.0-rc4 
root=UUID=39706f53-7c27-4310-b22a-36c7b042d1a1 ro radeon.audio=1
[    0.000000] Kernel command line: BOOT_IMAGE=/vmlinuz-4.1.0-rc4 
root=UUID=39706f53-7c27-4310-b22a-36c7b042d1a1 ro radeon.audio=1
[    0.000000] Console: colour VGA+ 80x25
[    0.343045] vgaarb: setting as boot device: PCI:0000:01:00.0
[    0.343090] vgaarb: device added: 
PCI:0000:01:00.0,decodes=io+mem,owns=io+mem,locks=none
[    0.343129] vgaarb: loaded
[    0.343163] vgaarb: bridge control possible 0000:01:00.0
[    0.675977] pci 0000:01:00.0: Video device with shadowed ROM
[   11.375968] [drm] Initialized drm 1.1.0 20060810
[   12.551021] [drm] radeon kernel modesetting enabled.
[   12.554304] [drm] initializing kernel modesetting (RV670 
0x1002:0x9505 0x1462:0x1121).
[   12.554392] [drm] register mmio base: 0xFEAF0000
[   12.554426] [drm] register mmio size: 65536
[   12.555340] radeon 0000:01:00.0: VRAM: 512M 0x0000000000000000 - 
0x000000001FFFFFFF (512M used)
[   12.555390] radeon 0000:01:00.0: GTT: 512M 0x0000000020000000 - 
0x000000003FFFFFFF
[   12.555428] [drm] Detected VRAM RAM=512M, BAR=256M
[   12.555462] [drm] RAM width 256bits DDR
[   12.556297] [TTM] Zone  kernel: Available graphics memory: 4076880 kiB
[   12.556338] [TTM] Zone   dma32: Available graphics memory: 2097152 kiB
[   12.556374] [TTM] Initializing pool allocator
[   12.556449] [TTM] Initializing DMA pool allocator
[   12.556988] [drm] radeon: 512M of VRAM memory ready
[   12.557024] [drm] radeon: 512M of GTT memory ready.
[   12.557122] [drm] Loading RV670 Microcode
[   13.087316] [drm] Internal thermal controller with fan control
[   13.087981] [drm] radeon: power management initialized
[   13.176411] [drm] GART: num cpu pages 131072, num gpu pages 131072
[   13.178975] [drm] PCIE gen 2 link speeds already enabled
[   13.185179] [drm] PCIE GART of 512M enabled (table at 
0x0000000000254000).
[   13.186166] radeon 0000:01:00.0: WB enabled
[   13.186245] radeon 0000:01:00.0: fence driver on ring 0 use gpu addr 
0x0000000020000c00 and cpu addr 0xffff88022257ac00
[   13.187262] radeon 0000:01:00.0: fence driver on ring 5 use gpu addr 
0x00000000000521d0 and cpu addr 0xffffc900004121d0
[   13.187336] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).
[   13.187397] [drm] Driver supports precise vblank timestamp query.
[   13.187459] radeon 0000:01:00.0: radeon: MSI limited to 32-bit
[   13.187614] radeon 0000:01:00.0: radeon: using MSI.
[   13.187774] [drm] radeon: irq initialized.
[   13.219524] [drm] ring test on 0 succeeded in 0 usecs
[   13.394018] [drm] ring test on 5 succeeded in 1 usecs
[   13.394060] [drm] UVD initialized successfully.
[   13.395087] [drm] ib test on ring 0 succeeded in 0 usecs
[   14.042416] [drm] ib test on ring 5 succeeded
[   14.049741] [drm] Radeon Display Connectors
[   14.049789] [drm] Connector 0:
[   14.049825] [drm]   DVI-I-1
[   14.049860] [drm]   HPD1
[   14.049896] [drm]   DDC: 0x7e50 0x7e50 0x7e54 0x7e54 0x7e58 0x7e58 
0x7e5c 0x7e5c
[   14.050022] [drm]   Encoders:
[   14.050061] [drm]     DFP1: INTERNAL_KLDSCP_TMDS1
[   14.050099] [drm]     CRT2: INTERNAL_KLDSCP_DAC2
[   14.050137] [drm] Connector 1:
[   14.050172] [drm]   DIN-1
[   14.050209] [drm]   Encoders:
[   14.050244] [drm]     TV1: INTERNAL_KLDSCP_DAC2
[   14.050284] [drm] Connector 2:
[   14.050318] [drm]   DVI-I-2
[   14.050351] [drm]   HPD2
[   14.050385] [drm]   DDC: 0x7e40 0x7e40 0x7e44 0x7e44 0x7e48 0x7e48 
0x7e4c 0x7e4c
[   14.050423] [drm]   Encoders:
[   14.050457] [drm]     CRT1: INTERNAL_KLDSCP_DAC1
[   14.050492] [drm]     DFP2: INTERNAL_LVTM1
[   14.110353] [drm] fb mappable at 0xD0355000
[   14.110396] [drm] vram apper at 0xD0000000
[   14.110430] [drm] size 8294400
[   14.110463] [drm] fb depth is 24
[   14.110496] [drm]    pitch is 7680
[   14.111750] fbcon: radeondrmfb (fb0) is primary device
[   14.148980] radeon 0000:01:00.0: fb0: radeondrmfb frame buffer device
[   14.149012] radeon 0000:01:00.0: registered panic notifier
[   14.158164] [drm] Initialized radeon 2.42.0 20080528 for 0000:01:00.0 
on minor 0
[   14.158710] snd_hda_intel 0000:01:00.1: Handle VGA-switcheroo audio 
client