kern/48496: uhub.c - usbd_new_device needs to be retried as many as 5 times for touch screen controller on Panasonic Toughbook CF19 mk5

[nathanialsloss%yahoo.com.au@localhost]

>Number:         48496
>Category:       kern
>Synopsis:       uhub.c - usbd_new_device needs to be retried as many as 5 
>times for touch screen controller on Panasonic Toughbook CF19 mk5
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sat Jan 04 01:05:00 +0000 2014
>Originator:     Nat Sloss
>Release:        NetBSD 6.1.1
>Organization:
>Environment:
NetBSD beast 6.1.1_PATCH NetBSD 6.1.1_PATCH (C3TEST) #0: Thu Jan  2 10:54:36 
EST 2014  build@microrusty:/usr/src/sys/arch/i386/compile/obj/C3TEST i386
>Description:
The touch screen controller on the Panasonic Toughbook CF19 mk5 is erratic.  
Sometimes it will attach first go but most often it wont and the port is 
disabled.

I found that retrying usbd_new_device up to 5 times fixes the problem.  

I don't know if the same results are obtained on an amd64 kernel I am still 
running an i386 kernel.
>How-To-Repeat:
Refer to above.
>Fix:
Apply this patch which retries usbd_new_device at most 8 times:

Index: sys/dev/usb/uhub.c
===================================================================
RCS file: /cvsroot/src/sys/dev/usb/uhub.c,v
retrieving revision 1.114.10.1
diff -u -r1.114.10.1 uhub.c
--- sys/dev/usb/uhub.c  19 Mar 2012 23:13:59 -0000      1.114.10.1
+++ sys/dev/usb/uhub.c  3 Jan 2014 23:55:31 -0000
@@ -544,6 +544,8 @@
                else
                        speed = USB_SPEED_FULL;
                /* Get device info and set its address. */
+               int new_device_tries = 8;
+newdev_retry:          
                err = usbd_new_device(sc->sc_dev, dev->bus,
                          dev->depth + 1, speed, port, up);
                /* XXX retry a few times? */
@@ -553,6 +555,16 @@
                        /* Avoid addressing problems by disabling. */
                        /* usbd_reset_port(dev, port, &up->status); */
 
+                       /* The touch screen controller on the Panasonic 
Toughbook CF19 - Mk 5
+                        * responds to new device erratically sometimes in as 
many as 5
+                        * attempts.
+                        */
+                       if (new_device_tries > 0) {
+                               new_device_tries--;
+                               delay(200);
+                               goto newdev_retry;
+                       }
+
                        /*
                         * The unit refused to accept a new address, or had
                         * some other serious problem.  Since we cannot leave

NB: This patch is my own work which I submit under the NetBSD license.

Regards,

Nat.