patch-2.4.25 linux-2.4.25/arch/ppc64/kernel/rtc.c

• Lines: 113
• Date: 2004-02-18 05:36:30.000000000 -0800
• Orig file: linux-2.4.24/arch/ppc64/kernel/rtc.c
• Orig date: 2004-01-05 05:53:56.000000000 -0800

diff -urN linux-2.4.24/arch/ppc64/kernel/rtc.c linux-2.4.25/arch/ppc64/kernel/rtc.c
@@ -33,6 +33,7 @@
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
 
+#include <asm/hardirq.h>
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -273,20 +274,63 @@
 }
 
 
+#define MAX_RTC_WAIT 5000	/* 5 sec */
+#define RTAS_CLOCK_BUSY (-2)
+void pSeries_get_boot_time(struct rtc_time *rtc_tm)
+{
+	unsigned long ret[8];
+	int error, wait_time;
+	unsigned long 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, (void *)&ret);
+		if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
+			wait_time = rtas_extended_busy_delay_time(error);
+			/* 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));
+
+	if (error != 0) {
+		printk(KERN_WARNING "error: reading the clock failed (%d)\n",
+			error);
+		return;
+	}
+
+	rtc_tm->tm_sec = ret[5];
+	rtc_tm->tm_min = ret[4];
+	rtc_tm->tm_hour = ret[3];
+	rtc_tm->tm_mday = ret[2];
+	rtc_tm->tm_mon = ret[1] - 1;
+	rtc_tm->tm_year = ret[0] - 1900;
+}
+
+/* NOTE: get_rtc_time will get an error if executed in interrupt context
+ * and if a delay is needed to read the clock.  In this case we just
+ * silently return without updating rtc_tm.
+ */
 void pSeries_get_rtc_time(struct rtc_time *rtc_tm)
 {
         unsigned long ret[8];
-        int error;
-	int count;
+	int error, wait_time;
+	unsigned long max_wait_tb;
 
-	/*
-	 * error -2 is clock busy, we keep retrying a few times to see
-	 * if it will come good  -- paulus
-	 */
-	count = 0;
+	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, (void *)&ret);
-	} while (error == -2 && ++count < 1000);
+		if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
+			if (in_interrupt()) {
+				printk(KERN_WARNING "error: reading clock would delay interrupt\n");
+				return;	/* delay not allowed */
+			}
+			wait_time = rtas_extended_busy_delay_time(error);
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(wait_time);
+			error = RTAS_CLOCK_BUSY;
+		}
+	} while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
 
         if (error != 0) {
                 printk(KERN_WARNING "error: reading the clock failed (%d)\n",
@@ -304,20 +348,24 @@
 
 int pSeries_set_rtc_time(struct rtc_time *tm)
 {
-        int error;
-	int count;
+	int error, wait_time;
+	unsigned long max_wait_tb;
 
-	/*
-	 * error -2 is clock busy, we keep retrying a few times to see
-	 * if it will come good  -- paulus
-	 */
-	count = 0;
+	max_wait_tb = __get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
 	do {
 	        error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
 				  tm->tm_year + 1900, tm->tm_mon + 1, 
 				  tm->tm_mday, tm->tm_hour, tm->tm_min, 
 				  tm->tm_sec, 0);
-	} while (error == -2 && ++count < 1000);
+		if (error == RTAS_CLOCK_BUSY || rtas_is_extended_busy(error)) {
+			if (in_interrupt())
+				return 1;	/* probably decrementer */
+			wait_time = rtas_extended_busy_delay_time(error);
+			set_current_state(TASK_INTERRUPTIBLE);
+			schedule_timeout(wait_time);
+			error = RTAS_CLOCK_BUSY;
+		}
+	} while (error == RTAS_CLOCK_BUSY && (__get_tb() < max_wait_tb));
 
         if (error != 0)
                 printk(KERN_WARNING "error: setting the clock failed (%d)\n",