diff options
| -rw-r--r-- | arch/arm/include/asm/cputype.h | 3 | ||||
| -rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 16 |
2 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h index 522b5feb4eaa..b62eaeb147aa 100644 --- a/arch/arm/include/asm/cputype.h +++ b/arch/arm/include/asm/cputype.h @@ -94,6 +94,9 @@ #define ARM_CPU_XSCALE_ARCH_V2 0x4000 #define ARM_CPU_XSCALE_ARCH_V3 0x6000 +/* Qualcomm implemented cores */ +#define ARM_CPU_PART_SCORPION 0x510002d0 + extern unsigned int processor_id; #ifdef CONFIG_CPU_CP15 diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 188180b5523d..be3b3fbd382f 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -1063,6 +1063,22 @@ static int __init arch_hw_breakpoint_init(void) return 0; } + /* + * Scorpion CPUs (at least those in APQ8060) seem to set DBGPRSR.SPD + * whenever a WFI is issued, even if the core is not powered down, in + * violation of the architecture. When DBGPRSR.SPD is set, accesses to + * breakpoint and watchpoint registers are treated as undefined, so + * this results in boot time and runtime failures when these are + * accessed and we unexpectedly take a trap. + * + * It's not clear if/how this can be worked around, so we blacklist + * Scorpion CPUs to avoid these issues. + */ + if (read_cpuid_part() == ARM_CPU_PART_SCORPION) { + pr_info("Scorpion CPU detected. Hardware breakpoints and watchpoints disabled\n"); + return 0; + } + has_ossr = core_has_os_save_restore(); /* Determine how many BRPs/WRPs are available. */ |