Hi Peter In case 2 the SIO-UART controller are not present (unplugged, physically not connected), and then the tty enumeration set the HSUART from ttys2 to ttyS0 and so the kernel message was printed physically to the wrong com port. Look the kernel message: Case 1: SIO-UART and PCI-HSUART are present 00:04: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A <-- Kernel message 00:05: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A 0000:00:1e.3: ttyS2 at MMIO 0x50705000 (irq = 18, base_baud = 2764800) is a 16550A <-- free to use 0000:00:1e.4: ttyS3 at MMIO 0x50707000 (irq = 16, base_baud = 2764800) is a 16550A Case 2: only PCI-HSUART are present 0000:00:1e.3: ttyS0 at MMIO 0x50705000 (irq = 18, base_baud = 2764800) is a 16550A <-- not free now with kernel message include 0000:00:1e.4: ttyS1 at MMIO 0x50707000 (irq = 16, base_baud = 2764800) is a 16550A We switch on the system in this 2 different cases. Case 1 is the service case and we can see when the kernel starts,... and so on. Case 1 the normal use without connected SIO-UART Controller. And so my idea was to change the device name for the pci uart. I hope this help you to understand my little problem. Alexander -----Ursprüngliche Nachricht----- Von: Peter Hurley [mailto:peter@xxxxxxxxxxxxxxxxxx] Gesendet: Mittwoch, 6. Mai 2015 12:14 An: Hänel-Baas, Alexander Cc: Greg KH; linux-serial@xxxxxxxxxxxxxxx Betreff: Re: AW: 8250_pci -> change device name On 05/06/2015 02:34 AM, Hänel-Baas, Alexander wrote: > Hi, > > thanks four your reply. > >> The right way to handle this would be to create a symlink in a udev script (or rc.d scripts if you don't have/use udev). >> Regards, >> Peter Hurley > >> Why not just change it in userspace using a tool like udev? Don't force the kernel to do something like this. >> thanks, >> greg k-h > > I have played with udev and yes i can create a symlink when the 8250_pci.ko is load. > But this is not the right solution for my problem: > > My System has a SIO-Uart pluggable over the PLC-Bus and a PCI ValleyView HSUART connected over the pci-bus. > > So the tty enumeration look like this: > SIO-UART -> ttyS0 -> this is the kernel console > -> ttyS1 > PCI-HSUART -> ttyS2 -> this is the console that can use by the userspace program > -> ttyS3 > > Case 2: the SIO-Uart is not connected. > PCI-HSUART -> ttyS0 -> and now the kernel prompt message and the userspace program too > -> ttyS1 It's not clear to me what you want to have happen in case 2. > In this case I need a free tty device for the PCI-HSUART and so I hope I can changed the device name only for the 8250_pci device to do this. > > Any ideas what can I do? > > Regards, > Alexander > > ��.n��������+%������w��{.n�����{��ǫ����{ay� ʇڙ���f���h������_�(�階�ݢj"��������G����?���&��
