Re: [PATCH v2 1/1] Input: atmel_mxt_ts - only read messages in mxt_acquire_irq() when necessary
From: Dmitry Torokhov
Date: Wed Jul 29 2020 - 01:55:00 EST
On Tue, Jul 28, 2020 at 12:16:37AM +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.
>
> Signed-off-by: Nick Dyer <nick.dyer@xxxxxxxxxxx>
> Acked-by: Benson Leung <bleung@xxxxxxxxxxxx>
> Acked-by: Yufeng Shen <miletus@xxxxxxxxxxxx>
> (cherry picked from ndyer/linux/for-upstream commit 1ae4e8281e491b22442cd5acdfca1862555f8ecb)
> [gdavis: Fix conflicts due to v4.6-rc7 commit eb43335c4095 ("Input:
> atmel_mxt_ts - use mxt_acquire_irq in mxt_soft_reset").]
> Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
> [jiada: reset use_retrigen_workaround at beginning of mxt_check_retrigen()
> call mxt_check_retrigen() after mxt_acquire_irq() in mxt_initialize()
> replace white-spaces with tab for MXT_COMMS_RETRIGEN
> Changed to check if IRQ is level type]
> Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
Applied, thank you.
--
Dmitry