Ok that does not really tell us anything more. So, debug time. Could you test the kernel below, you can run it in the 13.10 userspace no problem. Could you boot this kernel and get a dmesg output from it (which should contain additional info on why it fails). Kernels are at the URL below:
http://people.canonical.com/~apw/lp1313981-trusty/ Please report any testing here. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1313981 Title: Kernel disabling serial port ttyS0 on boot Status in “linux” package in Ubuntu: Confirmed Bug description: On boot in 13.10 kern.log would state: Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled 00:0a: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A and my serial modem would work just fine. After upgrading to 14.04 the kernel log contains: Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled serial 00:0a: disabled [[ Note that with the 3.13.0-24 kernel as reported in the bug below we see this: [ 3.191190] Serial: 8250/16550 driver, 32 ports, IRQ sharing enabled [ 3.191342] serial 00:0a: disabled ]] How do I enable 00:0a? Do I need to recompile the kernel with a different config? --- ApportVersion: 2.14.1-0ubuntu3 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: ubuntu-gnome 2581 F.... pulseaudio /dev/snd/controlC1: ubuntu-gnome 2581 F.... pulseaudio CasperVersion: 1.340 CurrentDesktop: GNOME DistroRelease: Ubuntu 14.04 LiveMediaBuild: Ubuntu-GNOME 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2) MachineType: System manufacturer System Product Name Package: linux (not installed) ProcEnviron: TERM=xterm PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/casper/vmlinuz.efi file=/cdrom/preseed/username.seed boot=casper quiet splash live-media=/dev/sdd1 -- ProcVersionSignature: Ubuntu 3.13.0-24.46-generic 3.13.9 RelatedPackageVersions: linux-restricted-modules-3.13.0-24-generic N/A linux-backports-modules-3.13.0-24-generic N/A linux-firmware 1.127 RfKill: 0: phy0: Wireless LAN Soft blocked: no Hard blocked: no Tags: trusty Uname: Linux 3.13.0-24-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo _MarkForUpload: True dmi.bios.date: 08/13/2013 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 2104 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: P8Z77-V dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr2104:bd08/13/2013:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnP8Z77-V:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1313981/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp