Re: [hatari-devel] SCU/VME register access?

[Christian Zietz <czietz@xxxxxxx>]

Nicolas Pomarède schrieb:

> 4) Nowhere else in the code do I see  that VEC_INT4 is used to set its
> vector (except in Falcon case). Maybe there's a not so explicit case
> that changes vectors[VEC_INT4], but I don't see it
>
> When VBL occurs we see it calls bad_inthandler that was set in 3), and
> not some random handler, so I think VBR is correctly used.
>
> All in all, it seems that the code enable vsync in TT mode but doesn't
> replace bad_inthandler with another valid handler.

Note that there *was* another user of 'IRQ_AUTO_4', i.e., the VBL 
interrupt. A VBL IRQ handler was set by the framebuffer console driver. 
However, this code was removed in 2009: 
https://github.com/torvalds/linux/commit/1fa0b29f3a43f9dd8080d24cd16790b15ef963f5.

I can imagine no one remembered back then to either disable the VBL IRQ 
on the TT or to install a dummy handler.

Regards
Christian
--
Christian Zietz  -  CHZ-Soft  -  czietz@xxxxxxx
WWW: https://www.chzsoft.de/
New GnuPG-Key-ID: 0x8708B34C827B159E