Re: [PATCH 2/3] aspeed-video: clear spurious interrupt bits unconditionally

[Zev Weiss]

On Mon, Dec 21, 2020 at 10:47:37PM CST, Joel Stanley wrote:
> On Tue, 15 Dec 2020 at 02:46, Zev Weiss <zev@xxxxxxxxxxxxxxxxx> wrote:
> > Instead of testing and conditionally clearing them one by one, we can
> > instead just unconditionally clear them all at once.
> >
> > Signed-off-by: Zev Weiss <zev@xxxxxxxxxxxxxxxxx>
>
> I had a poke at the assembly and it looks like GCC is clearing the
> bits unconditionally anyway, so removing the tests provides no change.
>
> Combining them is a good further optimization.
>
> Reviewed-by: Joel Stanley <joel@xxxxxxxxx>
>
> A question unrelated to this patch: Do you know why the driver doesn't
> clear the status bits in the interrupt handler? I would expect it to
> write the value of sts back to the register to ack the pending
> interrupt.

No, I don't, and I was sort of wondering the same thing actually -- I'm 
not deeply familiar with this hardware or driver though, so I was a bit 
hesitant to start messing with things.  (Though maybe doing so would 
address the "stickiness" aspect when it does manifest.)  Perhaps Eddie 
or Jae can shed some light here?


Zev