[PATCH] queue usb hotplug events

[Olaf Hering <olh@suse.de>]

Hi,

there is a hardcoded sleep 3 in the usb.agent. But this is wrong,
because the kernel runs all hotplug events at once for a new hub. The
result is that every event still runs in parallel, just 3 seconds later.

This patch implements an userland fifo.

touch an unique file
wait one second to let things settle
build a list with lockfiles, oldest last
grab the pid of the oldest agent
if this pid match the running agent, proceed
if all lockfiles are gone, proceed as well, provides a way to workaround
a hanging event
otherwise wait a second and try again


Index: etc/hotplug/usb.agent
=================================--- etc/hotplug/usb.agent	(revision 13)
+++ etc/hotplug/usb.agent	(working copy)
@@ -367,7 +367,15 @@
     # with slow HID devices and "usbmodules".
     # starting with 2.5, all hcds must queue control traffic.
     if [ "$DEVPATH" = "" ]; then
-	sleep 3
+	touch "${REMOVER}.queue.$$"
+    	until [ `sleep 1` ] ; do
+		lockfiles=`ls -t /var/run/usb/*.queue.* 2>/dev/null`
+		pid=${lockfiles##*.}
+		debug_mesg $pid $lockfiles
+		test "$pid" = "$$" && { debug_mesg pid $$ proceeds ; break; }
+		test "$lockfiles" = "" && { debug_mesg all lockfiles gone ; break; }
+		debug_mesg wait 1 second for pid $pid
+	done
     fi
 
     usb_convert_vars
@@ -426,6 +434,10 @@
         /sbin/devlabel restart
     fi
 
+    if [ -e "${REMOVER}.queue.$$" ]; then
+	debug_mesg pid $$ done
+	rm -f "${REMOVER}.queue.$$"
+    fi
     ;;
 
 remove)


-- 
USB is for mice, FireWire is for men!


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