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Diffstat (limited to 'arch/x86/kernel/cpu/amd.c')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 5398db4dedb4..ccaa51ce63f6 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -1355,11 +1355,23 @@ static __init int print_s5_reset_status_mmio(void) return 0; value = ioread32(addr); - iounmap(addr); /* Value with "all bits set" is an error response and should be ignored. */ - if (value == U32_MAX) + if (value == U32_MAX) { + iounmap(addr); return 0; + } + + /* + * Clear all reason bits so they won't be retained if the next reset + * does not update the register. Besides, some bits are never cleared by + * hardware so it's software's responsibility to clear them. + * + * Writing the value back effectively clears all reason bits as they are + * write-1-to-clear. + */ + iowrite32(value, addr); + iounmap(addr); for (i = 0; i < ARRAY_SIZE(s5_reset_reason_txt); i++) { if (!(value & BIT(i))) |