From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Mallett Subject: Re: baycom_ser_fdx - fixed under 2.6 Date: Mon, 28 Jul 2008 15:44:22 +1200 Message-ID: <488D4096.5000906@xnet.co.nz> References: <4885A8F6.7090109@free.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: David Robb , linux-hams@vger.kernel.org, David Miller , Ralf Baechle , Linux Netdev List To: Pidoux Return-path: In-Reply-To: <4885A8F6.7090109@free.fr> Sender: linux-hams-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Pidoux wrote: > Hi, > > This is a trivial but very important bug fix. Thanks David. > It was probably not submitted to the right destination and thus never > applied. > > This bug may have discouraged more than one radioamateur wishing to > experiment baycom style modems under Linux. > Fortunately you have done a very good historical search. > > I rebuilt the patch against 2.6.26 kernel (the only source I have here > on my laptop at my remote location during vacation). > > I Cc: to David Miller and Ralf Baechle DL5RB maintainers of Linux net > devices drivers and Linux AX25 drivers, respectively. > > 73 de Bernard, f6bvp > > > --- a/drivers/net/hamradio/hdlcdrv.c 2008-07-22 10:40:20.000000000 > +0200 > +++ b/drivers/net/hamradio/hdlcdrv.c 2008-07-22 10:42:13.000000000 > +0200 > @@ -88,6 +88,7 @@ > static inline void append_crc_ccitt(unsigned char *buffer, int len) > { > unsigned int crc = crc_ccitt(0xffff, buffer, len) ^ 0xffff; > + buffer += len; > *buffer++ = crc; > *buffer++ = crc >> 8; > } > > > > David Robb wrote : >> So it seems that I might be the only person in the world who's still >> attempting to use a Baycom bp-1 pocket modem under Linux, but oh well.. >> >> As a number of people noticed back in about 2005 (and some even >> earlier), the baycom_ser_fdx driver hasn't worked under Linux 2.6 for >> a few years (possibly ever). >> >> Various people poked around >> (http://osdir.com/ml/hams/2005-05/msg00022.html) and determined that >> there was some kind of packet corruption going on, and that the CRC >> was mangled. >> >> Well, after bashing my head against it a few times over the last few >> months (I guess I was bored), and finally thinking that it mightn't >> be in the baycom_ser_fdx driver that the problem actually was, I >> tracked it down to the hdlcdrv code instead... >> >> Someone called Micah actually figured this out in 2004, and submitted >> a patch, but it never made it into the kernel (at least in my >> 2.6.25.7 it's still broken): >> >> http://linux.derkeiler.com/Mailing-Lists/Kernel/2004-11/2929.html >> >> The CRC's overwriting some of the packet... >> >> So anyway, applying the patch listed at that URL (1 line! Just one >> little line!) my BP-1 now works again under 2.6.25. >> >> Perhaps I'm strange for wanting this working in these days of high >> speed links, but hey... it seems sad to have broken code and no >> support where there used to be a functional device. >> >> Anyway, share and enjoy. >> >> --David ZL3UDR > -- > To unsubscribe from this list: send the line "unsubscribe linux-hams" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Hi, The Baycom MoDem problem is one I have battled for quite a while here. How do I apply this patch to my Ubuntu 2.6.20-17-generic kernel. I have the linux-source-2.6.20-2.6.20 source so which file do I apply the patch too ? Then I need to recompile it ? Would this bug also affect the SCC Baycom card ? Regards ..... Peter