Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Mon, 25 May 2020 10:46:10 +0200 | Subject | Re: [PATCH] m68k/mac: Avoid stuck ISM IOP interrupt on Quadra 900/950 |
| |
On Wed, May 20, 2020 at 6:41 AM Finn Thain <fthain@telegraphics.com.au> wrote: > On a Quadra 900/950, the ISM IOP IRQ output pin is connected to an > edge-triggered input on VIA2. It is theoretically possible that this > signal could fail to produce the expected VIA2 interrupt. > > The two IOP interrupt flags can be asserted in any order but the logic > in iop_ism_irq() does not allow for that. In particular, INT0 can be > asserted right after INT0 is checked and before INT1 is cleared. > > Such an interrupt would produce no new edge and VIA2 would detect no > further interrupts from the IOP. Avoid this by looping over the INT0/1 > handlers so an edge can be produced. > > Cc: Joshua Thompson <funaho@jurai.org> > Tested-by: Stan Johnson <userm57@yahoo.com> > Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> i.e. will queue in the m68k for-v5.8 branch.
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
| |