Re: [PATCH] Due to some broken bitfiles, we can't trust IntCtl

[Ralf Baechle <ralf@linux-mips.org>]

On Fri, Jul 10, 2009 at 01:49:43AM -0700, Raghu Gandham wrote:

> diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
> index 09b08d0..ca0b5ed 100644
> --- a/arch/mips/include/asm/irq.h
> +++ b/arch/mips/include/asm/irq.h
> @@ -158,6 +158,7 @@ extern void free_irqno(unsigned int irq);
>   * IE7.  Since R2 their number has to be read from the c0_intctl register.
>   */
>  #define CP0_LEGACY_COMPARE_IRQ 7
> +#define CP0_LEGACY_PERFCNT_IRQ 7
>  
>  extern int cp0_compare_irq;
>  extern int cp0_perfcount_irq;
> diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
> index 08f1edf..0b6e328 100644
> --- a/arch/mips/kernel/traps.c
> +++ b/arch/mips/kernel/traps.c
> @@ -1538,7 +1538,11 @@ void __cpuinit per_cpu_trap_init(void)
>  	 */
>  	if (cpu_has_mips_r2) {
>  		cp0_compare_irq = (read_c0_intctl() >> 29) & 7;
> +		if (!cp0_compare_irq)
> +			cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
>  		cp0_perfcount_irq = (read_c0_intctl() >> 26) & 7;
> +		if (!cp0_perfcount_irq)
> +			cp0_perfcount_irq = CP0_LEGACY_PERFCNT_IRQ;
>  		if (cp0_perfcount_irq == cp0_compare_irq)
>  			cp0_perfcount_irq = -1;
>  	} else {

Is there still any point in applying this patch?  I thought only a bunch
of early bitfiles were affected but it was never actually taped out?

  Ralf