Re: APM driver patch summary

Russell King
2001-12-17T22:22:46Z

On Mon, Dec 17, 2001 at 10:04:02PM +0000, Russell King wrote:
> On Mon, Dec 17, 2001 at 01:28:13PM -0500, Thomas Hood wrote:
> > Each of these changes is required, IMHO. However, the Russell King
> > patch probably won't apply without modifications. Also, it needs to
> > be modified so that it will send a resume event to listeners in case
> > a driver rejects a suspend event that listeners have already
> > processed.
>
> It does do that - check the suspend() function.

Actually you're right, it doesn't send a resume event. However, It's
worse than that - it will leave all sleeping listeners still sleeping.

Try this patch instead - this should cause all listeners to get a -EIO
to indicate that the suspend failed, and also get the resume event.

Thanks for finding that. This (untested) patch should fix the problem.
(difference is in suspend()):

--- orig/arch/i386/kernel/apm.c Fri Nov 23 10:12:07 2001
+++ linux/arch/i386/kernel/apm.c Mon Dec 17 22:20:03 2001
@@ -1133,40 +1133,22 @@
#endif
}

-static int send_event(apm_event_t event)
-{
- switch (event) {
- case APM_SYS_SUSPEND:
- case APM_CRITICAL_SUSPEND:
- case APM_USER_SUSPEND:
- /* map all suspends to ACPI D3 */
- if (pm_send_all(PM_SUSPEND, (void *)3)) {
- if (event == APM_CRITICAL_SUSPEND) {
- printk(KERN_CRIT
- "apm: Critical suspend was vetoed, "
- "expect armageddon\n" );
- return 0;
- }
- if (apm_info.connection_version > 0x100)
- apm_set_power_state(APM_STATE_REJECT);
- return 0;
- }
- break;
- case APM_NORMAL_RESUME:
- case APM_CRITICAL_RESUME:
- /* map all resumes to ACPI D0 */
- (void) pm_send_all(PM_RESUME, (void *)0);
- break;
- }
-
- return 1;
-}
-
-static int suspend(void)
+static int suspend(int vetoable)
{
int err;
struct apm_user *as;

+ if (pm_send_all(PM_SUSPEND, (void *)3)) {
+ if (!vetoable) {
+ printk(KERN_CRIT
+ "apm: suspend was vetoed, expect armageddon\n");
+ } else if (apm_info.connection_version > 0x100) {
+ apm_set_power_state(APM_STATE_REJECT);
+ err = -EIO;
+ goto out;
+ }
+ }
+
get_time_diff();
cli();
err = apm_set_power_state(APM_STATE_SUSPEND);
@@ -1176,12 +1158,17 @@
err = APM_SUCCESS;
if (err != APM_SUCCESS)
apm_error("suspend", err);
- send_event(APM_NORMAL_RESUME);
sti();
+
+ pm_send_all(PM_RESUME, (void *)0);
+
+ err = (err == APM_SUCCESS) ? 0 : -EIO;
+
+ out:
queue_event(APM_NORMAL_RESUME, NULL);
for (as = user_list; as != NULL; as = as->next) {
as->suspend_wait = 0;
- as->suspend_result = ((err == APM_SUCCESS) ? 0 : -EIO);
+ as->suspend_result = err;
}
ignore_normal_resume = 1;
wake_up_interruptible(&apm_suspend_waitqueue);
@@ -1241,11 +1228,9 @@
switch (event) {
case APM_SYS_STANDBY:
case APM_USER_STANDBY:
- if (send_event(event)) {
- queue_event(event, NULL);
- if (standbys_pending <= 0)
- standby();
- }
+ queue_event(event, NULL);
+ if (standbys_pending <= 0)
+ standby();
break;

case APM_USER_SUSPEND:
@@ -1270,12 +1255,10 @@
*/
if (waiting_for_resume)
return;
- if (send_event(event)) {
- queue_event(event, NULL);
- waiting_for_resume = 1;
- if (suspends_pending <= 0)
- (void) suspend();
- }
+ queue_event(event, NULL);
+ waiting_for_resume = 1;
+ if (suspends_pending <= 0)
+ (void) suspend(1);
break;

case APM_NORMAL_RESUME:
@@ -1287,7 +1270,7 @@
if ((event != APM_NORMAL_RESUME)
|| (ignore_normal_resume == 0)) {
set_time();
- send_event(event);
+ pm_send_all(PM_RESUME, (void *)0);
queue_event(event, NULL);
}
break;
@@ -1295,7 +1278,6 @@
case APM_CAPABILITY_CHANGE:
case APM_LOW_BATTERY:
case APM_POWER_STATUS_CHANGE:
- send_event(event);
queue_event(event, NULL);
break;

@@ -1304,12 +1286,11 @@
break;

case APM_CRITICAL_SUSPEND:
- send_event(event);
/*
* We can only hope it worked - we are not allowed
* to reject a critical suspend.
*/
- (void) suspend();
+ (void) suspend(0);
break;
}
}
@@ -1479,9 +1460,7 @@
as->standbys_read--;
as->standbys_pending--;
standbys_pending--;
- } else if (!send_event(APM_USER_STANDBY))
- return -EAGAIN;
- else
+ } else
queue_event(APM_USER_STANDBY, as);
if (standbys_pending <= 0)
standby();
@@ -1491,13 +1470,10 @@
as->suspends_read--;
as->suspends_pending--;
suspends_pending--;
- } else if (!send_event(APM_USER_SUSPEND))
- return -EAGAIN;
- else
+ } else
queue_event(APM_USER_SUSPEND, as);
if (suspends_pending <= 0) {
- if (suspend() != APM_SUCCESS)
- return -EIO;
+ return suspend(1);
} else {
as->suspend_wait = 1;
wait_event_interruptible(apm_suspend_waitqueue,
@@ -1528,7 +1504,7 @@
if (as->suspends_pending > 0) {
suspends_pending -= as->suspends_pending;
if (suspends_pending <= 0)
- (void) suspend();
+ (void) suspend(1);
}
if (user_list == as)
user_list = as->next;

--
Russell King (rmk@arm.linux.org.uk) The developer of ARM Linux