Dear Tapan, The message "Couldn't register serial port " in the dmesg log does NOT come from the Intel 537 driver but from another driver. [philippe@victor ~]$ grep "Couldn't register serial port " intel-536-537/* [philippe@victor ~]$ grep "Couldn't register serial port " intel-536-537/*/*.c [philippe@victor ~]$ Regards, - http://vouters.dyndns.org:8080/ Philippe Vouters (Fontainebleau/France) Le jeudi 18 juin 2009 à 09:07 +0530, Tapan Chugh a écrit : > > Dear Philippe, > > I found this line interesting in the dmesg log > > "Couldn't register serial port 0000:04:00.0: -28" > > also the modem is on 04:00.0 as detected by lspci > > "04:00.0 Modem: SILICON Laboratories Intel 537 [Winmodem] (rev 04)" > >