Would you like to try another patch? :-)
This is rather longer than needed, it has some tidy ups from Thomas
Hood as well. I have basically simplified the idle loop and added
a couple of more points where it can escape.
I am not seeing your problems, but then again I am running on an IBM
Thinkpad, so I do BIOS calls with interrupts enabled and the BIOS halts
on idle (as opposed to slowing the CPU). I also have SpeedStep
disabled.
-- Cheers, Stephen Rothwell sfr@canb.auug.org.au http://www.canb.auug.org.au/~sfr/diff -ruN 2.4.18-pre7/arch/i386/kernel/apm.c 2.4.18-pre7-APM.1/arch/i386/kernel/apm.c --- 2.4.18-pre7/arch/i386/kernel/apm.c Thu Jan 24 11:33:54 2002 +++ 2.4.18-pre7-APM.1/arch/i386/kernel/apm.c Tue Jan 29 22:56:09 2002 @@ -380,7 +380,7 @@ static int set_pm_idle; static int suspends_pending; static int standbys_pending; -static int waiting_for_resume; +static int ignore_sys_suspend; static int ignore_normal_resume; static int bounce_interval = DEFAULT_BOUNCE_INTERVAL; @@ -761,15 +761,6 @@ } } -/* - * If no process has really been interested in - * the CPU for some time, we want to call BIOS - * power management - we probably want - * to conserve power. - */ -#define IDLE_CALC_LIMIT (HZ * 100) -#define IDLE_LEAKY_MAX 16 - static void (*sys_idle)(void); extern void default_idle(void); @@ -777,28 +768,24 @@ /** * apm_cpu_idle - cpu idling for APM capable Linux * - * This is the idling function the kernel executes when APM is available. It - * tries to do BIOS powermanagement based on the average system idle time. - * Furthermore it calls the system default idle routine. + * This is the idling function the kernel executes when APM is available. + * It tries to do BIOS power management based on the average system + * idle time. Furthermore it calls the system idle routines. */ static void apm_cpu_idle(void) { - static int use_apm_idle = 0; - static unsigned int last_jiffies = 0; - static unsigned int last_stime = 0; - - int apm_is_idle = 0; - unsigned int jiffies_since_last_check = jiffies - last_jiffies; - unsigned int t1; + static int use_apm_idle; + static unsigned int last_jiffies; + static unsigned int last_stime; + int apm_idle_done = 0; + unsigned int jiffies_since_last_check; + + jiffies_since_last_check = jiffies - last_jiffies; recalc: - if (jiffies_since_last_check > IDLE_CALC_LIMIT) { - use_apm_idle = 0; - last_jiffies = jiffies; - last_stime = current->times.tms_stime; - } else if (jiffies_since_last_check > idle_period) { + if (jiffies_since_last_check > idle_period) { unsigned int idle_percentage; idle_percentage = current->times.tms_stime - last_stime; @@ -809,39 +796,33 @@ last_stime = current->times.tms_stime; } - t1 = IDLE_LEAKY_MAX; - while (!current->need_resched) { if (use_apm_idle) { - unsigned int t; + unsigned int t = jiffies; - t = jiffies; switch (apm_do_idle()) { - case 0: apm_is_idle = 1; - if (t != jiffies) { - if (t1) { - t1 = IDLE_LEAKY_MAX; - continue; - } - } else if (t1) { - t1--; + case 0: apm_idle_done = 1; + if (t != jiffies) continue; - } break; - case 1: apm_is_idle = 1; + case 1: apm_idle_done = 1; break; } } + if (current->need_resched) + break; if (sys_idle) sys_idle(); else default_idle(); + if (current->need_resched) + break; jiffies_since_last_check = jiffies - last_jiffies; if (jiffies_since_last_check > idle_period) goto recalc; } - if (apm_is_idle) + if (apm_idle_done) apm_do_busy(); } @@ -1196,7 +1177,7 @@ if (apm_info.connection_version > 0x100) apm_set_power_state(APM_STATE_REJECT); err = -EBUSY; - waiting_for_resume = 0; + ignore_sys_suspend = 0; printk(KERN_WARNING "apm: suspend was vetoed.\n"); goto out; } @@ -1295,16 +1276,15 @@ break; } /* - * If we are already processing a SUSPEND, - * then further SUSPEND events from the BIOS - * will be ignored. We also return here to - * cope with the fact that the Thinkpads keep - * sending a SUSPEND event until something else - * happens! + * If we are already processing a SUSPEND, then + * further SUSPEND events from the BIOS should + * be ignored. We have to check for this because + * Thinkpads keep sending SUSPEND events until + * something else happens! */ - if (waiting_for_resume) + if (ignore_sys_suspend) return; - waiting_for_resume = 1; + ignore_sys_suspend = 1; queue_event(event, NULL); if (suspends_pending <= 0) (void) suspend(1); @@ -1313,7 +1293,7 @@ case APM_NORMAL_RESUME: case APM_CRITICAL_RESUME: case APM_STANDBY_RESUME: - waiting_for_resume = 0; + ignore_sys_suspend = 0; last_resume = jiffies; ignore_bounce = 1; if ((event != APM_NORMAL_RESUME) @@ -1381,7 +1361,7 @@ if (exit_kapmd) break; /* - * Ok, check all events, check for idle (and mark us sleeping + * Ok, check all events (and mark us sleeping * so as not to count towards the load average).. */ set_current_state(TASK_INTERRUPTIBLE); @@ -1455,6 +1435,11 @@ return 0; } +/* + * Note that the drivers may reject a suspend request. + * When this happens, no suspend is done, and the ioctl() + * returns the EBUSY error code to the user. + */ static int do_ioctl(struct inode * inode, struct file *filp, u_int cmd, u_long arg) { - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/