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authorTiezhu Yang <yangtiezhu@loongson.cn>2021-04-06 11:25:12 +0200
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2021-04-06 15:12:58 +0200
commit5e65c52ec716af6e8f51dacdaeb4a4d872249af1 (patch)
tree569805a219c86da29a43ac1d91c68b6679f7afa6 /arch
parentMIPS: Remove get_fs/set_fs (diff)
downloadlinux-5e65c52ec716af6e8f51dacdaeb4a4d872249af1.tar.xz
linux-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')
-rw-r--r--arch/mips/kernel/cpu-probe.c3
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!");