linux-kernel - Re: [PATCH v2 1/1] Input: atmel_mxt_ts - only read messages in mxt_acquire

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Message-ID: <20200729055449.GX1665100@dtor-ws>
Date:   Tue, 28 Jul 2020 22:54:49 -0700
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Jiada Wang <jiada_wang@...tor.com>
Cc:     nick@...anahar.org, linux-input@...r.kernel.org,
        linux-kernel@...r.kernel.org, erosca@...adit-jv.com,
        Andrew_Gabbasov@...tor.com, digetx@...il.com
Subject: Re: [PATCH v2 1/1] Input: atmel_mxt_ts - only read messages in
 mxt_acquire_irq() when necessary

On Tue, Jul 28, 2020 at 12:16:37AM +0900, Jiada Wang wrote:
> From: Nick Dyer <nick.dyer@...ev.co.uk>
> 
> 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@...ev.co.uk>
> Acked-by: Benson Leung <bleung@...omium.org>
> Acked-by: Yufeng Shen <miletus@...omium.org>
> (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@...tor.com>
> [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@...tor.com>

Applied, thank you.

-- 
Dmitry