Summary: | [bisected] bump map corruption from kernel 3.5 | ||
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Product: | Mesa | Reporter: | Joeri Capens <joeri> |
Component: | Drivers/Gallium/r600 | Assignee: | Default DRI bug account <dri-devel> |
Status: | RESOLVED INVALID | QA Contact: | |
Severity: | normal | ||
Priority: | medium | ||
Version: | 7.11 | ||
Hardware: | x86-64 (AMD64) | ||
OS: | Linux (All) | ||
Whiteboard: | |||
i915 platform: | i915 features: | ||
Attachments: |
Portal 2 screenshot - good
Portal 2 screenshot - bad bisect info num_shader_engines Xorg.0.log evergreen_fix_tile_config_and_remove_unused_variable.patch Portal 2 screenshot - Linux GIT evergreen_fix_tile_config_and_remove_unused_variable_v2.patch |
Created attachment 65541 [details]
Portal 2 screenshot - bad
Created attachment 65542 [details]
bisect info
Forgot to mention: while trying (but failing) to narrow down the problem with patch 416a2bd274566a6f607a271f524b2dc0b84d9106 I found that variable num_shader_engines in evergreen.c appears to be unused? Please attach the Xorg.0.log file corresponding to the problem. Have you tried current Mesa Git master? Adding Xorg.0.log. I tried the latest Mesa Git now but it didn't make a difference. However, I found the specific change in 416a2bd274566a6f607a271f524b2dc0b84d9106 which causes the bump map corruption I'm seeing. When I revert the change in the tile_config calculation, the problem goes away. I've created a patch which fixes the tile_config calculation and which removes the unused num_shader_engines variable. Created attachment 65572 [details]
num_shader_engines
Created attachment 65573 [details]
Xorg.0.log
Created attachment 65574 [details] [review] evergreen_fix_tile_config_and_remove_unused_variable.patch (In reply to comment #8) > Created attachment 65574 [details] [review] [review] > evergreen_fix_tile_config_and_remove_unused_variable.patch That patch is wrong. group size has no relation to burst size. I think what's happening is that increasing group size is causing larger alignment. Does this patch help? http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=c8d15edc17d836686d1f071e564800e1a2724fa6 I actually already tried that patch since I tried the last Linux GIT two days ago. Unfortunately it doesn't fix the problem. The screen corruption does look a bit different though, see attachment "16_bank.png". Adding a printk for the tile_config value right after its calculation gives me the following values: Linux 3.4: 0x1112 (good) Linux 3.5: 0x1012 (corruption) Linux GIT: 0x0022 (slightly less corruption) Does this information help? Created attachment 65617 [details]
Portal 2 screenshot - Linux GIT
Bit 8 of tile_config (CHANSIZE?) needs to be 1 to make the bumpmap corruption disappear on my system. Before 416a2bd274566a6f607a271f524b2dc0b84d9106 this used to be calculated from the BURSTLENGTH value. My patch reverted to that and while it works it does indeed look weird. Patch 416a2bd274566a6f607a271f524b2dc0b84d9106 replaced the calculation with: rdev->config.evergreen.tile_config |= 0 << 8; which also looks weird because this operation does nothing. So I guess it must simply be: rdev->config.evergreen.tile_config |= 1 << 8; I don't have a clue what all of this actually means or does to the hardware, it only seems more logical to me and it fixes the problems I was having. The value of tile_config is now 0x0122 on my system. Attaching a new patch. Created attachment 66427 [details] [review] evergreen_fix_tile_config_and_remove_unused_variable_v2.patch I re-compiled mesa again (the "8.1_rc1_pre20120724" git snapshot provided by Gentoo, to be exact) and this time the bump map corruption does not occur anymore, with or without my kernel patch. I tried some recent mesa versions before, but I must have made mistakes while copying the mesa libraries from a 32-bit chroot to the /usr/lib32/ directory on my 64-bit system. Somewhere between mesa 8.0.4 and the snapshot of 2012-07-24, the bug has already been fixed. |
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Created attachment 65540 [details] Portal 2 screenshot - good After updating my Linux kernel to 3.5.0 I'm seeing bump map corruption in Portal 2. See attachments. I bisected it down to commit 416a2bd274566a6f607a271f524b2dc0b84d9106 - drm/radeon: fixup tiling group size and backendmap on r6xx-r9xx (v4) My GPU is a Radeon HD 5670 (Evergreen, Redwood) and I'm using Gallium (for R600) on Gentoo Linux AMD64. If I disable bump mapping in Portal 2 (command "mat_bumpmap 0") the corruption goes away, but obviously the walls and objects appear flatter. Mesa, libdrm, xf86-video-ati or Wine versions don't seem to matter. I tested some combinations of Mesa 7.11.2 and 8.0.4, libdrm 2.4.27, 2.4.33 and 2.4.38, xf86-video-ati 6.14.4 and 6.14.6, Wine 1.5.9 and 1.5.10.