Re: [PATCH v1 03/63] Input: atmel_mxt_ts - only read messages in mxt_acquire_irq() when necessary

[Jiada Wang]

Hi Dmitry

On 2019/08/17 2:16, Dmitry Torokhov wrote:
> On Fri, Aug 16, 2019 at 05:28:52PM +0900, Jiada Wang wrote:
> > From: Nick Dyer <nick.dyer@xxxxxxxxxxx>
> >
> > The workaround of reading all messages until an invalid is received is a
> > way of forcing the CHG line high, which means that when using
> > edge-triggered interrupts the interrupt can be acquired.
> >
> > With level-triggered interrupts the workaround is unnecessary.
> >
> > Also, most recent maXTouch chips have a feature called RETRIGEN which, when
> > enabled, reasserts the interrupt line every cycle if there are messages
> > waiting. This also makes the workaround unnecessary.
> >
> > Note: the RETRIGEN feature is only in some firmware versions/chips, it's
> > not valid simply to enable the bit.
>
> Instead of trying to work around of misconfiguration for IRQ/firmware,
> can we simply error out of probe if we see a level interrupt with
> !RETRIGEN firmware?
I think for old firmwares, which doesn't support RETRIGEN feature, this 
workaround is needed, otherwise we will break all old firmwares, which 
configured with edge-triggered IRQ

for recent firmwares which support RETRIGEN feature, we can fail probe, 
if RETRIGEN is not enabled, and configured with edge-triggered IRQ.

what is your thought?

Thanks,
Jiada
> Thanks.