[PATCH] powerpc: reorg RTAS delay code
This patch attempts to handle RTAS "busy" return codes in a more simple
and consistent manner. Typical callers of RTAS shouldn't have to
manage wait times and delay calls.
This patch also changes the kernel to use msleep() rather than udelay()
when a runtime delay is necessary. This will avoid CPU soft lockups
for extended delay conditions.
Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/rtas-rtc.c b/arch/powerpc/kernel/rtas-rtc.c
index 34d073fb..77578c0 100644
--- a/arch/powerpc/kernel/rtas-rtc.c
+++ b/arch/powerpc/kernel/rtas-rtc.c
@@ -14,19 +14,20 @@
unsigned long __init rtas_get_boot_time(void)
{
int ret[8];
- int error, wait_time;
+ int error;
+ unsigned int wait_time;
u64 max_wait_tb;
max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
do {
error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
- if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
- wait_time = rtas_extended_busy_delay_time(error);
+
+ wait_time = rtas_busy_delay_time(error);
+ if (wait_time) {
/* This is boot time so we spin. */
udelay(wait_time*1000);
- error = RTAS_CLOCK_BUSY;
}
- } while (error == RTAS_CLOCK_BUSY && (get_tb() < max_wait_tb));
+ } while (wait_time && (get_tb() < max_wait_tb));
if (error != 0 && printk_ratelimit()) {
printk(KERN_WARNING "error: reading the clock failed (%d)\n",
@@ -44,24 +45,25 @@
void rtas_get_rtc_time(struct rtc_time *rtc_tm)
{
int ret[8];
- int error, wait_time;
+ int error;
+ unsigned int wait_time;
u64 max_wait_tb;
max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
do {
error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
- if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
+
+ wait_time = rtas_busy_delay_time(error);
+ if (wait_time) {
if (in_interrupt() && printk_ratelimit()) {
memset(rtc_tm, 0, sizeof(struct rtc_time));
printk(KERN_WARNING "error: reading clock"
" would delay interrupt\n");
return; /* delay not allowed */
}
- wait_time = rtas_extended_busy_delay_time(error);
msleep(wait_time);
- error = RTAS_CLOCK_BUSY;
}
- } while (error == RTAS_CLOCK_BUSY && (get_tb() < max_wait_tb));
+ } while (wait_time && (get_tb() < max_wait_tb));
if (error != 0 && printk_ratelimit()) {
printk(KERN_WARNING "error: reading the clock failed (%d)\n",
@@ -88,14 +90,14 @@
tm->tm_year + 1900, tm->tm_mon + 1,
tm->tm_mday, tm->tm_hour, tm->tm_min,
tm->tm_sec, 0);
- if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
+
+ wait_time = rtas_busy_delay_time(error);
+ if (wait_time) {
if (in_interrupt())
return 1; /* probably decrementer */
- wait_time = rtas_extended_busy_delay_time(error);
msleep(wait_time);
- error = RTAS_CLOCK_BUSY;
}
- } while (error == RTAS_CLOCK_BUSY && (get_tb() < max_wait_tb));
+ } while (wait_time && (get_tb() < max_wait_tb));
if (error != 0 && printk_ratelimit())
printk(KERN_WARNING "error: setting the clock failed (%d)\n",