MPC8245/1 UARTs and linux-2.6.13-rc5

MPC8245/1 UARTs and linux-2.6.13-rc5

[Kumar Gala]

For all people have issues with the UARTs on MPC8245/1.  In the  
2.6.13 kernel we reworked the support for UARTs to be platform  
devices.  If you look at the 2.6.13-rc5 release you will see the  
changes that went in.  Additionally, the sandpoint reference platform  
code was updated to take advantage of the changes.

Hopefully, these changes will make some of the issues you might be  
facing less of a problem.

- kumar 

Re: MPC8245/1 UARTs and linux-2.6.13-rc5

[Daniel Ann]

Kumar,

Just on the subject, I'm finding that I have to define STD_COM_FLAGS
with ASYNC_SKIP_TEST to get my 8245 uart to display on console.
Purpose of ASYNC_SKIP_TEST is to skip below section of code found in
8250.c
[snip]
static void autoconfig(struct uart_8250_port *up, unsigned int probeflags)
[snip]
    if (!(up->port.flags & UPF_SKIP_TEST)) {
        serial_outp(up, UART_MCR, UART_MCR_LOOP | 0x0A);
        status1 =3D serial_inp(up, UART_MSR) & 0xF0;
        serial_outp(up, UART_MCR, save_mcr);
        if (status1 !=3D 0x90) {
            DEBUG_AUTOCONF("LOOP test failed (%02x) ",
                       status1);
            goto out;
        }
    }
[end]
If I dont skip, then kernel boots up fine, with all the kernel printk,
but from /sbin/init onwards, I get no display and looking at the uart
interrupt using debugger, I see that interrupt hasnt been enabled. But
if I skip, all works like a charm.

Any idea why ?


On 8/2/05, Kumar Gala <kumar.gala@freescale.com> wrote:
> For all people have issues with the UARTs on MPC8245/1.  In the
> 2.6.13 kernel we reworked the support for UARTs to be platform
> devices.  If you look at the 2.6.13-rc5 release you will see the
> changes that went in.  Additionally, the sandpoint reference platform
> code was updated to take advantage of the changes.
>=20
> Hopefully, these changes will make some of the issues you might be
> facing less of a problem.
>=20
> - kumar
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
>=20


--=20
Daniel