Am Freitag, 2. März 2007 17:03 schrieb Alan Stern:
> On Thu, 1 Mar 2007, Oliver Neukum wrote:
>
> > > Actually I had in mind something simpler, like getting rid of the
> > > GET_DESCRIPTOR_TRIES loop for i (or reducing it to one attempt using the
> > > new scheme and one attempt using the old scheme) and getting rid of the
> > > SET_ADDRESS_TRIES loop for j, both in hub_port_init().
> >
> > I would prefer to try very hard once. This is what this patch does.
>
> Take a look at this log from a little over a year ago:
>
> http://marc.theaimsgroup.com/?l=linux-usb-devel&m=113521633114762&w=2
>
> Len Brown had a docking station with an internal hub that wasn't working
> right. It is device 3-5; we start trying to enumerate it at time stamp
> 40.129703 and give up at timestamp 103.761001. That's just ridiculous.
> Not to mention unfriendly, since khubd is unavailable for anything else
> during that time _and_ it holds the root hub's device lock, preventing
> many other things from working.
>
> Trying hard is fine, but to keep on trying for over 60 seconds is foolish.
How about this one?
Regards
Oliver
--- linux-2.6.20-giveup/drivers/usb/core/hub.c.orig 2007-03-06
13:18:46.000000000 +0100
+++ linux-2.6.20-giveup/drivers/usb/core/hub.c 2007-03-06 13:24:38.000000000
+0100
@@ -70,6 +70,7 @@
unsigned has_indicators:1;
u8 indicator[USB_MAXCHILDREN];
+ unsigned long last_failed[USB_MAXCHILDREN];
struct delayed_work leds;
};
@@ -2410,7 +2411,7 @@
struct usb_device *hdev = hub->hdev;
struct device *hub_dev = hub->intfdev;
u16 wHubCharacteristics =
le16_to_cpu(hub->descriptor->wHubCharacteristics);
- int status, i;
+ int status, i, retries, timeouts = 0;
dev_dbg (hub_dev,
"port %d, status %04x, change %04x, %s\n",
@@ -2438,7 +2439,7 @@
dev_err (hub_dev,
"connect-debounce failed, port %d disabled\n",
port1);
- goto done;
+ goto failed;
}
portstatus = status;
}
@@ -2452,7 +2453,7 @@
set_port_feature(hdev, port1, USB_PORT_FEAT_POWER);
if (portstatus & USB_PORT_STAT_ENABLE)
- goto done;
+ goto failed;
return;
}
@@ -2469,7 +2470,11 @@
}
#endif
- for (i = 0; i < SET_CONFIG_TRIES; i++) {
+ /* we give short shrift if we had a failure within the last 2 hours */
+ retries = hub->last_failed[port1 - 1] &&
+ time_after(hub->last_failed[port1 - 1] + HZ * 60 * 60 * 2,
jiffies) ?
+ 1 : SET_CONFIG_TRIES;
+ for (i = 0; i < retries; i++) {
struct usb_device *udev;
/* reallocate for each attempt, since references
@@ -2571,6 +2576,7 @@
if (status)
dev_dbg(hub_dev, "%dmA power budget left\n", status);
+ hub->last_failed[port1 - 1] = 0; /*all former errors forgiven */
return;
loop_disable:
@@ -2579,10 +2585,18 @@
ep0_reinit(udev);
release_address(udev);
usb_put_dev(udev);
+ if (status == -ETIMEDOUT)
+ timeouts++;
+ else
+ timeouts = 0;
if (status == -ENOTCONN)
break;
+ if (timeouts >= 3) /* number taken from US law */
+ break;
}
-
+
+failed:
+ hub->last_failed[port1 - 1] = jiffies;
done:
hub_port_disable(hub, port1, 1);
}
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