diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 795225d7f138..86aff1cb8a0d 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -606,6 +606,47 @@ unsigned int rtas_busy_delay_time(int status) return ms; } +/* + * Early boot fallback for rtas_busy_delay(). + */ +static bool __init rtas_busy_delay_early(int status) +{ + static size_t successive_ext_delays __initdata; + bool retry; + + switch (status) { + case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX: + /* + * In the unlikely case that we receive an extended + * delay status in early boot, the OS is probably not + * the cause, and there's nothing we can do to clear + * the condition. Best we can do is delay for a bit + * and hope it's transient. Lie to the caller if it + * seems like we're stuck in a retry loop. + */ + mdelay(1); + retry = true; + successive_ext_delays += 1; + if (successive_ext_delays > 1000) { + pr_err("too many extended delays, giving up\n"); + dump_stack(); + retry = false; + successive_ext_delays = 0; + } + break; + case RTAS_BUSY: + retry = true; + successive_ext_delays = 0; + break; + default: + retry = false; + successive_ext_delays = 0; + break; + } + + return retry; +} + /** * rtas_busy_delay() - helper for RTAS busy and extended delay statuses * @@ -624,11 +665,17 @@ unsigned int rtas_busy_delay_time(int status) * * false - @status is not @RTAS_BUSY nor an extended delay hint. The * caller is responsible for handling @status. */ -bool rtas_busy_delay(int status) +bool __ref rtas_busy_delay(int status) { unsigned int ms; bool ret; + /* + * Can't do timed sleeps before timekeeping is up. + */ + if (system_state < SYSTEM_SCHEDULING) + return rtas_busy_delay_early(status); + switch (status) { case RTAS_EXTENDED_DELAY_MIN...RTAS_EXTENDED_DELAY_MAX: ret = true; |