kern/116347: APM does not suspend USB devices

[Marko Zec]

>Number:         116347
>Category:       kern
>Synopsis:       APM does not suspend USB devices
>Confidential:   no
>Severity:       non-critical
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Fri Sep 14 12:20:03 GMT 2007
>Closed-Date:
>Last-Modified:
>Originator:     Marko Zec
>Release:        7.0-CURRENT
>Organization:
U. of Zagreb
>Environment:
FreeBSD tpx32.icir.org 7.0-CURRENT FreeBSD 7.0-CURRENT #6: Fri Sep 14 09:32:49 CEST 2007     marko at tpx32.icir.org:/u/marko/p4/vimage/src/sys/i386/compile/TPX32V  i386

>Description:
Any USB device attached to a machine running APM instead of ACPI won't survive a suspend/resume cycle.
>How-To-Repeat:
Boot with ACPI disabled / APM enabled, plug in a USB device, suspend, resume, done.
>Fix:
See the patch attached.

Patch attached with submission follows:

--- ../head/src/sys/i386/bios/apm.c	2007-08-31 03:47:17.000000000 +0200
+++ src/sys/i386/bios/apm.c	2007-09-14 10:20:46.000000000 +0200
@@ -485,7 +485,13 @@ apm_do_suspend(void)
 	apm_op_inprog = 0;
 	sc->suspends = sc->suspend_countdown = 0;
 
+	/*
+	 * Be sure to hold Giant across DEVICE_SUSPEND/RESUME since
+	 * non-MPSAFE drivers need this.
+	 */
+	mtx_lock(&Giant);
 	error = DEVICE_SUSPEND(root_bus);
+	mtx_unlock(&Giant);
 	if (error)
 		return;
 
@@ -496,7 +502,9 @@ apm_do_suspend(void)
 	} else {
 		/* Failure, 'resume' the system again */
 		apm_execute_hook(hook[APM_HOOK_RESUME]);
+		mtx_lock(&Giant);
 		DEVICE_RESUME(root_bus);
+		mtx_unlock(&Giant);
 	}
 	return;
 }
@@ -602,7 +610,9 @@ apm_resume(void)
 
 	sc->suspending = 0;
 	apm_execute_hook(hook[APM_HOOK_RESUME]);
+	mtx_lock(&Giant);
 	DEVICE_RESUME(root_bus);
+	mtx_unlock(&Giant);
 	return;
 }
 


>Release-Note:
>Audit-Trail:
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