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| author |   Tiezhu Yang <yangtiezhu@loongson.cn> | 2021-04-06 17:25:12 +0800 |
|---|---|---|
| committer |   Thomas Bogendoerfer <tsbogend@alpha.franken.de> | 2021-04-06 15:12:58 +0200 |
| commit | 5e65c52ec716af6e8f51dacdaeb4a4d872249af1 (patch) | |
| tree | 569805a219c86da29a43ac1d91c68b6679f7afa6 /arch/mips/kernel/cpu-probe.c | |
| parent | MIPS: Remove get_fs/set_fs (diff) | |
| download | linux-dev-5e65c52ec716af6e8f51dacdaeb4a4d872249af1.tar.xz linux-dev-5e65c52ec716af6e8f51dacdaeb4a4d872249af1.zip | |
MIPS: Loongson64: Use _CACHE_UNCACHED instead of _CACHE_UNCACHED_ACCELERATED
Loongson64 processors have a writecombine issue that maybe failed to
write back framebuffer used with ATI Radeon or AMD GPU at times, after
commit 8a08e50cee66 ("drm: Permit video-buffers writecombine mapping
for MIPS"), there exists some errors such as blurred screen and lockup,
and so on.
[ 60.958721] radeon 0000:03:00.0: ring 0 stalled for more than 10079msec
[ 60.965315] radeon 0000:03:00.0: GPU lockup (current fence id 0x0000000000000112 last fence id 0x000000000000011d on ring 0)
[ 60.976525] radeon 0000:03:00.0: ring 3 stalled for more than 10086msec
[ 60.983156] radeon 0000:03:00.0: GPU lockup (current fence id 0x0000000000000374 last fence id 0x00000000000003a8 on ring 3)
As discussed earlier [1], it might be better to disable writecombine
on the CPU detection side because the root cause is unknown now.
Actually, this patch is a temporary solution to just make it work well,
it is not a proper and final solution, I hope someone will have a better
solution to fix this issue in the future.
[1] https://lore.kernel.org/patchwork/patch/1285542/
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips/kernel/cpu-probe.c')
| -rw-r--r-- | arch/mips/kernel/cpu-probe.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c index b71892064f27..0ef240adefb5 100644 --- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -1752,7 +1752,6 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) set_isa(c, MIPS_CPU_ISA_M64R2); break; } - c->writecombine = _CACHE_UNCACHED_ACCELERATED; c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2); break; @@ -1782,7 +1781,6 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) * register, we correct it here. */ c->options |= MIPS_CPU_FTLB | MIPS_CPU_TLBINV | MIPS_CPU_LDPTE; - c->writecombine = _CACHE_UNCACHED_ACCELERATED; c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM | MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2); c->ases &= ~MIPS_ASE_VZ; /* VZ of Loongson-3A2000/3000 is incomplete */ @@ -1793,7 +1791,6 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu) set_elf_platform(cpu, "loongson3a"); set_isa(c, MIPS_CPU_ISA_M64R2); decode_cpucfg(c); - c->writecombine = _CACHE_UNCACHED_ACCELERATED; break; default: panic("Unknown Loongson Processor ID!"); |