On Wed, Jan 25, 2006 at 12:18:39AM +0000, Carl Perry wrote: > Greg KH <gregkh <at> suse.de> writes: > > > > > From: David Hollis <dhollis <at> davehollis.com> > > > > USB: Add device id's for Novatel Wireless CDMA wireless PC card. > > The Novatel CDMA card behaves the same as the AirPrime by providing > > a USB serial port. > > > > Signed-off-by: David Hollis <dhollis <at> davehollis.com> > > Signed-off-by: Greg Kroah-Hartman <gregkh <at> suse.de> > > > > Now that this driver is in the kernel (I'm running 2.6.15), there are some > problems I'd like to report when using it. Basically, Junxion found this > problem as well and posted a patch > [http://www.junxion.com/opensource/linux_highspeed_usbserial.html]. I know it > solves the problem, but the solution may be worse than the disease.
It can't solve the problem, as that is a 2.4 patch :) And it just papers over any possible issue, it doesn't solve anything. > Here is the problem, when you are moving "large" amounts of data or have a > very > high packet rate then the driver starts wigging out. The device will send > data > to the terminal, but it cannot recieve data - or visa versa. The only way to > recover from this is disconnect the device and reconnect it. The Junxion > patch > simply increases the size of the buffer for the driver. I don't know if the > reason this is needed is a problem with the Qualcomm EVOD Modem device itself > or > there is a bug in the serial driver. My money is on the former ;) > > So, is my real question is: Is this patch the solution? Is there a betetr > solution? I have tried to get the data sheet for the EVDO Qualcomm chip, but > I > can't seem to find it or get anyone to talk to me. What's the next step? No, the patch is not the solution. The real way to fix this is to figure out how we add flow control to these devices. It looks like the device overruns, and stops sending data, and waits for the host to renenable something to continue the flow. Right now we don't know how to do that at all. So, I would go ask the manufacturer for this kind of information, as we (well me at least) have no idea of what is needed to do to fix this issue, sorry. thanks, greg k-h ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Do you grep through log files for problems? Stop! Download the new AJAX search engine that makes searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
