On Wed, Sep 17, 2025 at 11:14:45AM -0400, Nick Bowler wrote:
> On Fri, Aug 29, 2025 at 03:07:14PM +0200, Thomas Zimmermann wrote:
> > The ast driver doesn't do much during shutdown. Could you please out-comment
> > the lines at either [2] xor [3] and report on either effect? These calls
> > turn of the video chip's memory access and sync pulses. Not doing that might
> > resolve the problem.
> >
> > [2]
> > https://elixir.bootlin.com/linux/v6.16.3/source/drivers/gpu/drm/ast/ast_mode.c#L835
> > [3]
> > https://elixir.bootlin.com/linux/v6.16.3/source/drivers/gpu/drm/ast/ast_mode.c#L839
>
> I can try this.
OK, I tested 6.17-rc6 and reproduced the problem on this version. Then:
- Deleting [2] (only) appears to make no difference whatsoever. That
is, deleting the following line in ast_mode.c:
ast_set_index_reg_mask(ast, AST_IO_VGASRI, 0x01, 0xdf, AST_IO_VGASR1_SD);
- Deleting [3] (only) appears sufficient to make things work again,
that is, deleting the following line in ast_mode.c:
ast_set_index_reg_mask(ast, AST_IO_VGACRI, 0xb6, 0xfc, vgacrb6);
Thanks,
Nick
