Re: [PATCH] Re: usb-serial ipaq kernel problem

From: Frank Gevaerts
Date: Tue May 23 2006 - 09:30:56 EST


On Tue, May 23, 2006 at 12:04:59AM +0200, Frank Gevaerts wrote:
> On Mon, May 22, 2006 at 02:44:03PM -0700, Greg KH wrote:
> > On Mon, May 22, 2006 at 04:30:48PM +0200, Frank Gevaerts wrote:
> > > Hi,
> > >
> > > We are having problems with the usb-serial ipaq driver in 2.6.16 (debian
> > > backports 2.6.16-1-686, but also reproducible with self-compiled
> > > kernel.org kernel)
> > >
> > > Sometimes, we get the following on disconnect:
> >
> > <snip>
> >
> > Can you duplicate this on 2.6.17-rc4? A number of tty changes went into
> > that release that should have fixed this issue.
>
> I'll try it in the morning. In the meantime, we found some other
> problems in ipaq.c : apparently pocketpc accepts usb enumeration long
> before it accepts usb-serial commands (sometimes 50 or more seconds),
> which makes ipaq_open fail. When it fails, the read urb is not killed,
> while the associated structures are freed, which gives a panic when
> the urb completes. The following patch solves that :
> Since changing this, I also have not seen the original problem anymore,
> but I will do some more testing tomorrow.

I cannot reproduce the original problem anymore with my patch applied

Frank

>
> Signed-off-by: Frank Gevaerts <frank.gevaerts@xxxxxx>
>
> --- linux-2.6.16/drivers/usb/serial/ipaq.c 2006-03-20 06:53:29.000000000 +0100
> +++ linux-2.6.16.ipaq/drivers/usb/serial/ipaq.c 2006-05-23 00:00:33.000000000 +0200
> @@ -59,7 +59,7 @@
> #include "usb-serial.h"
> #include "ipaq.h"
>
> -#define KP_RETRIES 100
> +#define KP_RETRIES 1000
>
> /*
> * Version Information
> @@ -652,12 +652,6 @@
> usb_rcvbulkpipe(serial->dev, port->bulk_in_endpointAddress),
> port->read_urb->transfer_buffer, port->read_urb->transfer_buffer_length,
> ipaq_read_bulk_callback, port);
> - result = usb_submit_urb(port->read_urb, GFP_KERNEL);
> - if (result) {
> - err("%s - failed submitting read urb, error %d", __FUNCTION__, result);
> - goto error;
> - }
> -
> /*
> * Send out control message observed in win98 sniffs. Not sure what
> * it does, but from empirical observations, it seems that the device
> @@ -671,8 +665,15 @@
> usb_sndctrlpipe(serial->dev, 0), 0x22, 0x21,
> 0x1, 0, NULL, 0, 100);
> if (result == 0) {
> + result = usb_submit_urb(port->read_urb, GFP_KERNEL);
> + if (result) {
> + err("%s - failed submitting read urb, error %d", __FUNCTION__, result);
> + goto error;
> + }
> +
> return 0;
> }
> + msleep(100);
> }
> err("%s - failed doing control urb, error %d", __FUNCTION__, result);
> goto error;
>
> >
> > thanks,
> >
> > greg k-h
> >
>
> --
> Frank Gevaerts frank.gevaerts@xxxxxx
> fks bvba - Formal and Knowledge Systems http://www.fks.be/
> Stationsstraat 108 Tel: ++32-(0)11-21 49 11
> B-3570 ALKEN Fax: ++32-(0)11-22 04 19

--
Frank Gevaerts frank.gevaerts@xxxxxx
fks bvba - Formal and Knowledge Systems http://www.fks.be/
Stationsstraat 108 Tel: ++32-(0)11-21 49 11
B-3570 ALKEN Fax: ++32-(0)11-22 04 19
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