Re: [PATCH v6 1/1] MIPS: Fix idle VS timer enqueue

[Maciej W. Rozycki]

On Sat, 15 Mar 2025, Marco Crivellari wrote:

> diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
> index a572ce36a24f..4e012421d00f 100644
> --- a/arch/mips/kernel/genex.S
> +++ b/arch/mips/kernel/genex.S
> @@ -104,27 +104,30 @@ handle_vcei:
>  
>  	__FINIT
>  
> -	.align	5	/* 32 byte rollback region */
> +	.align	5
>  LEAF(__r4k_wait)
>  	.set	push
>  	.set	noreorder
> -	/* start of rollback region */
> -	LONG_L	t0, TI_FLAGS($28)
> -	nop
> -	andi	t0, _TIF_NEED_RESCHED
> -	bnez	t0, 1f
> -	 nop
> -	nop
> -	nop
> -#ifdef CONFIG_CPU_MICROMIPS
> -	nop
> -	nop
> -	nop
> -	nop
> -#endif
> +	/* Start of idle interrupt region. */
> +	MFC0	t0, CP0_STATUS
> +	/* Enable interrupt. */
> +	ori 	t0, 0x1f

 This instruction sequence still suffers from the coprocessor move delay 
hazard.  How many times do I need to request to get it fixed (counting 
three so far)?

  Maciej