Re: USB extension (repeater) cable

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On Sun, 21 Jan 2007, Udo van den Heuvel wrote:

H. Peter Anvin wrote:
Greg KH wrote:
On Fri, Jan 19, 2007 at 04:40:34PM +0100, Udo van den Heuvel wrote:

I just tried my shiny new usb extension cable (repeater):

Jan 19 16:01:17 epia kernel: usb 5-1: new high speed USB device using
ehci_hcd and address 60
Jan 19 16:01:17 epia kernel: usb 5-1: configuration #1 chosen from 1
choice
Jan 19 16:01:17 epia kernel: hub 5-1:1.0: USB hub found
Jan 19 16:01:17 epia kernel: hub 5-1:1.0: 4 ports detected
Jan 19 16:01:18 epia kernel: hub 5-1:1.0: Cannot enable port 1.  Maybe
the USB cable is bad?
Jan 19 16:01:22 epia last message repeated 3 times
Jan 19 16:01:23 epia kernel: hub 5-1:1.0: Cannot enable port 2.  Maybe
the USB cable is bad?
Jan 19 16:01:26 epia last message repeated 3 times
Jan 19 16:01:27 epia kernel: hub 5-1:1.0: Cannot enable port 3.  Maybe
the USB cable is bad?
Jan 19 16:01:31 epia last message repeated 3 times

[...]

Actually, what it looks like is even simpler.  The extension cable
contains a four-port hub chip (which is the most common commodity chip)
and haven't bothered changing the descriptor to tell the computer only
one port is actually active.  So only one port can be activated, and the
others are stubbed out in some evil way.  In that case, it should be
noisy but harmless.

I will do some more testing then.
Is there a way to get rid of the messages?

I am using the following patch (with 2.6.17) to shut up these messages with my repeater cable - found it on the linux-usb mailinglist some time ago when facing the same problem, but did not write down from who it is.

(Does not silence all log messages when usb debugging is enabled, but when it is disabled there is no endless log-stream anymore and the cable works)

I tried to fix the logging-change to the usb id, but the cable uses exactly the same chip and id as the two chips inside my 7port usb-hub.


Index: linux/drivers/usb/core/hub.c
===================================================================
--- linux.orig/drivers/usb/core/hub.c	2006-10-14 00:45:50.000000000 +0200
+++ linux/drivers/usb/core/hub.c	2006-10-14 00:47:38.000000000 +0200
@@ -1496,7 +1496,8 @@

 		/* bomb out completely if something weird happened */
 		if ((portchange & USB_PORT_STAT_C_CONNECTION))
-			return -EINVAL;
+			//return -EINVAL;
+			return -ENOTCONN;

 		/* if we`ve finished resetting, then break out of the loop */
 		if (!(portstatus & USB_PORT_STAT_RESET) &&

c'ya
sven

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