Re: usb_control_msg() reads 0 bytes in Linux 2.6.23-rc1
Alan Stern <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Tue, 24 Jul 2007, Pete Zaitcev wrote: > On Tue, 24 Jul 2007 01:55:26 -0400, Pavel Roskin <[email protected]> wrote: > > > The driver stopped working after I upgraded from Linux 2.6.22 to Linux > > 2.6.23-rc1. No compile errors or warnings needed to be fixed. > > > I was able to check that the data buffer remains unchanged even though > > the data size is not 0. Actually, the return code is 0, which indicates > > that 0 bytes have been read. But why? And why is it not an error? > > I looked at the changes in -rc1 and the only two vaguely suspicious areas > are the suspend and the ehci_hcd. So, I'm afraid someone has to bisect. > > The URB_SHORT_NOT_OK flag is not default. I don't remember exactly why. > > > I'll appreciate if some of the USB developers have a brief look at the > > driver. Sure, I can debug deeper into usb_control_msg(), but most > > likely the driver is just doing something stupid. > > > > The patch for the kernel: > > http://80211libre.org/at76/at76_usb.patch > > I don't see anything suspicious in the patch. 2.6.23-rc1 has no apparent problem with control messages in ehci-hcd on my machine. Is it possible that the device really has sent back 0 bytes? usbmon might help here. Alan Stern ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel