Serial core: 8250_pci could not register serial port for UART chip EXAR XR17D152

Serial core: 8250_pci could not register serial port for UART chip EXAR XR17D152

[V. ANANDA KRISHNAN]

Hi all,

  I have been coming across a problem with my serial port EXAR chip XR
17D152, when I try to use the 8250_pci driver.  I am using
kernel-2.6.12.1 on RHEL4.0-U1 on pSeries box with 4-cpu.  8250_pci
during the boot time, after detecting the exar chip (I checked with the
pci_dev structure and the pci_device_id structure for the info), is
unable to get thru the port registration (static int
__devinit_pciserial_init_one(struct pci_dev *dev, const struct
pci_device_id *ent) procedure in 8250_pci.c).  I debugged the problem
and traced upto the routine "static int uart_match_port(struct uart_port
*port1, struct uart_port *port2" in 8250.c where UPIO_MEM is not
satisfying the condition port1->membase==port2->membase and hence
returns 0.

  If I use the printk for dumping the port-> membase value the system
hags during the boot time with a blank screen (on the serial terminal).
I am yet to try with kernel-2.6.12.2.  Please let me know how to proceed
in this case.  Thanks,
V.Ananda Krishnan

Re: Serial core: 8250_pci could not register serial port for UART chip EXAR XR17D152

[Russell King]

On Thu, Jul 14, 2005 at 11:47:29AM -0500, V. ANANDA KRISHNAN wrote:
>   I have been coming across a problem with my serial port EXAR chip XR
> 17D152, when I try to use the 8250_pci driver.  I am using
> kernel-2.6.12.1 on RHEL4.0-U1 on pSeries box with 4-cpu.  8250_pci
> during the boot time, after detecting the exar chip (I checked with the
> pci_dev structure and the pci_device_id structure for the info), is
> unable to get thru the port registration (static int
> __devinit_pciserial_init_one(struct pci_dev *dev, const struct
> pci_device_id *ent) procedure in 8250_pci.c).  I debugged the problem
> and traced upto the routine "static int uart_match_port(struct uart_port
> *port1, struct uart_port *port2" in 8250.c where UPIO_MEM is not
> satisfying the condition port1->membase==port2->membase and hence
> returns 0.

That's the intended result.  uart_match_port() only returns true when
the types of the two ports match, and the base address of the two ports
also match.

Please try mainline 2.6 kernels.  Also, please include the kernel entire
messages when reporting bugs.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core