5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jiaxun Yang jiaxun.yang@flygoat.com
commit 1cb6ab446424649f03c82334634360c2e3043684 upstream.
Loongson64 C and G processors have EXTIMER feature which is conflicting with CP0 counter.
Although the processor resets in EXTIMER disabled & INTIMER enabled mode, which is compatible with MIPS CP0 compare, firmware may attempt to enable EXTIMER and interfere CP0 compare.
Set timer mode back to MIPS compatible mode to fix booting on systems with such firmware before we have an actual driver for EXTIMER.
Cc: stable@vger.kernel.org Signed-off-by: Jiaxun Yang jiaxun.yang@flygoat.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/mips/kernel/cpu-probe.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/arch/mips/kernel/cpu-probe.c +++ b/arch/mips/kernel/cpu-probe.c @@ -1782,12 +1782,16 @@ static inline void cpu_probe_loongson(st 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 */ + change_c0_config6(LOONGSON_CONF6_EXTIMER | LOONGSON_CONF6_INTIMER, + LOONGSON_CONF6_INTIMER); break; case PRID_IMP_LOONGSON_64G: __cpu_name[cpu] = "ICT Loongson-3"; set_elf_platform(cpu, "loongson3a"); set_isa(c, MIPS_CPU_ISA_M64R2); decode_cpucfg(c); + change_c0_config6(LOONGSON_CONF6_EXTIMER | LOONGSON_CONF6_INTIMER, + LOONGSON_CONF6_INTIMER); break; default: panic("Unknown Loongson Processor ID!");