Subject: Re: reboot of mpc8270 sometimes fails

From: Theo Gjaltema <[email-masked]>
Date: Thu, 01 Nov 2007 19:02:59 +0100

Hi!

I solved our problem a different way: I added a reset of the CPM just 
before calling te m8260_gorom().
The effect is that the message "rebooting" which was often followed by a 
strange character is now cut short ("reboo"), but uboot is always 
comming up afterwards. I've tested this by adding a "reboot" command in 
an S script in rc3.d. The system with the unpatched kernel failed 
aboutonce every 30 times it rebooted, with the patch it continued 
rebooting correctly for 3 days (then I stopped the tests by hand).

The code for rebooting the CPM was obtained from the freescale manuals 
of the mpc8270.
Anyone interested in the actual patch?

Theo.

Matvejchikov Ilya schreef:
> Hi!
>
> I thik that m8260_restart in 2.4 kernel is broken. Try to get it from
> the 2.6 kernel, or look at this.
>
>  /* The 8260 has an internal 1-second timer update register that
> @@ -112,21 +123,16 @@ m8260_get_rtc_time(void)
>  static void
>  m8260_restart(char *cmd)
>  {
> -	extern void m8260_gorom(bd_t *bi, uint addr);
> -	uint	startaddr;
> -
> -	/* Most boot roms have a warmstart as the second instruction
> -	 * of the reset vector.  If that doesn't work for you, change this
> -	 * or the reboot program to send a proper address.
> -	 */
> -	startaddr = 0xff000104;
> -
> -	if (cmd != NULL) {
> -		if (!strncmp(cmd, "startaddr=", 10))
> -			startaddr = simple_strtoul(&cmd[10], NULL, 0);
> -	}
> -
> -	m8260_gorom((unsigned int)__pa(__res), startaddr);
> +	__volatile__ unsigned char dummy;
> +	
> +	local_irq_disable();
> +	((cpm2_map_t *) cpm2_immr)->im_clkrst.car_rmr |= 0x00000001;
> +
> +	/* Clear the ME,EE,IR & DR bits in MSR to cause checkstop */
> +	mtmsr(mfmsr() & ~(MSR_ME | MSR_EE | MSR_IR | MSR_DR));
> +	dummy = ((cpm2_map_t *) cpm2_immr)->im_clkrst.res[0];
> +	printk("Restart failed\n");
> +	while (1) ;
>  }
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