Re: [PATCH 3/5 gnumach] linux: No need to init PIT timer twice

[Samuel Thibault]

Mmmm, I believe we do? linux_init() is called before
cpu_launch_first_thread(), and some Linux drivers may need the clock
ticking for their probing.

Note however that we don't plan to keep Linux drivers on the long run:
once rumpdisk is confirmed to be stable we'll just get rid of the Linux
drivers, so I'd say it's not worth trying to fix things here in the APIC
case.

Damien Zammit, le mer. 01 févr. 2023 10:05:58 +0000, a ecrit:
> ---
>  linux/dev/arch/i386/kernel/irq.c | 12 ++----------
>  linux/dev/init/main.c            |  2 ++
>  2 files changed, 4 insertions(+), 10 deletions(-)
> 
> diff --git a/linux/dev/arch/i386/kernel/irq.c 
> b/linux/dev/arch/i386/kernel/irq.c
> index 67feea84..5f221da1 100644
> --- a/linux/dev/arch/i386/kernel/irq.c
> +++ b/linux/dev/arch/i386/kernel/irq.c
> @@ -421,7 +421,7 @@ reserve_mach_irqs (void)
>  {
>    unsigned int i;
> 
> -  for (i = 0; i < NINTR; i++)
> +  for (i = 1; i < NINTR; i++)
>      {
>        if (ivect[i] != intnull)
>       /* This dummy action does not specify SA_SHIRQ, so
> @@ -707,7 +707,6 @@ void
>  init_IRQ (void)
>  {
>    char *p;
> -  int latch = (CLKNUM + hz / 2) / hz;
> 
>    /*
>     * Ensure interrupts are disabled.
> @@ -715,19 +714,12 @@ init_IRQ (void)
>    (void) splhigh ();
> 
>  #ifndef APIC
> -  /*
> -   * Program counter 0 of 8253 to interrupt hz times per second.
> -   */
> -  outb_p (PIT_C0 | PIT_SQUAREMODE | PIT_READMODE, PITCTL_PORT);
> -  outb_p (latch & 0xff, PITCTR0_PORT);
> -  outb (latch >> 8, PITCTR0_PORT);
> -#endif
> -
>    /*
>     * Install our clock interrupt handler.
>     */
>    old_clock_handler = ivect[0];
>    ivect[0] = linux_timer_intr;
> +#endif
> 
>    reserve_mach_irqs ();
> 
> diff --git a/linux/dev/init/main.c b/linux/dev/init/main.c
> index 6d853957..207724f3 100644
> --- a/linux/dev/init/main.c
> +++ b/linux/dev/init/main.c
> @@ -160,7 +160,9 @@ linux_init (void)
>    pcmcia_init ();
>  #endif
> 
> +#ifndef APIC
>    restore_IRQ ();
> +#endif
> 
>    linux_auto_config = 0;
>  }
> --
> 2.34.1