Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH] x86/i8259: Work around buggy legacy PIC | Date | Fri, 14 May 2021 19:32:54 +0200 |
| |
On Fri, May 14 2021 at 13:58, Maximilian Luz wrote: > On 5/14/21 9:41 PM, Sachi King wrote: > I'd assume that _some_ sort of interrupt setup is done by the BIOS/UEFI. > The UEFI on those devices is fairly well-featured, with touch support > via SPI and all. Furthermore, keyboard (also supported in the device's > UEFI) is handled via a custom UART protocol. Unless they rely on polling > for all of that, I believe they'd have to set up some interrupts.
Polling would be truly surprising.
> Although, as you mention later on, that could also be handled via the > IOAPIC and the PIC is actually not supposed to be used. Maybe some > legacy component that never got tested and just broke with some new > hardware/firmware revision without anyone noticing? And since Linux > still seems to rely on that, we might be the first to notice.
That's a valid assumption. As I said, we can make IOAPIC work even w/o PIC. I'll have a look how much PIC assumptions are still around.
Thanks,
tglx
| |