From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH 2/2] input: touch: eeti: read hardware state once after wakeup References: <20190422083540.8380-1-daniel@zonque.org> <20190422083540.8380-2-daniel@zonque.org> <20190423031705.gllzrreptvphdrc3@penguin> <6b550519-4550-0872-f3de-9eba1fc0279f@zonque.org> <20190423084111.hqco2xgl2lfe35la@penguin> <20190428173604.GB44908@dtor-ws> From: Daniel Mack Message-ID: Date: Sun, 28 Apr 2019 21:30:19 +0200 MIME-Version: 1.0 In-Reply-To: <20190428173604.GB44908@dtor-ws> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit To: Dmitry Torokhov Cc: robh+dt@kernel.org, linux-input@vger.kernel.org, devicetree@vger.kernel.org, Sven Neumann List-ID: On 28/4/2019 7:36 PM, Dmitry Torokhov wrote: > On Sun, Apr 28, 2019 at 09:18:46AM +0200, Daniel Mack wrote: >> On 23/4/2019 10:41 AM, Dmitry Torokhov wrote: >>> On Tue, Apr 23, 2019 at 06:51:32AM +0200, Daniel Mack wrote: >>>> Hi Dmitry, >>>> >>>> On 23/4/2019 5:17 AM, Dmitry Torokhov wrote: >>>>> On Mon, Apr 22, 2019 at 10:35:40AM +0200, Daniel Mack wrote: >>>>>> For systems in which the touch IRQ is acting as wakeup source, the interrupt >>>>>> controller might not latch the GPIO IRQ during sleep. In such cases, the >>>>>> interrupt will never occur again after resume, hence the touch screen >>>>>> appears dead. >>>>>> >>>>>> To fix this, call into eeti_ts_read() once to read the hardware status and >>>>>> to arm the IRQ again. >>>>> >>>>> Can you instead make the interrupt level-triggered? >>>> >>>> The hardware I'm working on doesn't support that unfortunately. >>>> >>>> In fact, the whole attn-gpio dance is there because of that, and the >>>> GPIO descriptor maps to the same pin that also causes the IRQ in my case. >>> >>> OK, if the interrupt controller is incapable of dealing with level >>> interrupts then we have to do what you propose. >> >> So you consider these patches for inclusion then? I'm just asking >> because I can't see them in your tree yet. > > I was about to, but now I wonder if we need a mutex in the isr code now, > otherwise there is a chance it will be running concurrently when we are > resuming if interrupt does latch. Ah, good point. I'll send a v2. Thanks, Daniel