From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH 2/3] Input: zforce - enable irq only if we are ready to process it Date: Sun, 19 Jul 2015 23:35:23 -0700 Message-ID: <20150720063523.GD13092@dtor-ws> References: <1436791779-21798-1-git-send-email-dirk.behme@de.bosch.com> <1436791779-21798-2-git-send-email-dirk.behme@de.bosch.com> <20150713170735.GC5039@dtor-ws> <55A4AEEF.4020300@de.bosch.com> <20150717215847.GD39282@dtor-ws> <55AC84D9.2080809@de.bosch.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f50.google.com ([209.85.220.50]:36052 "EHLO mail-pa0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754500AbbGTGf1 (ORCPT ); Mon, 20 Jul 2015 02:35:27 -0400 Received: by pachj5 with SMTP id hj5so96968069pac.3 for ; Sun, 19 Jul 2015 23:35:27 -0700 (PDT) Content-Disposition: inline In-Reply-To: <55AC84D9.2080809@de.bosch.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: "external.Oleksij.Rempel" Cc: Dirk Behme , linux-input@vger.kernel.org On Mon, Jul 20, 2015 at 07:19:21AM +0200, external.Oleksij.Rempel wrote: > Hi Dmitry, > > > On 17.07.2015 23:58, Dmitry Torokhov wrote: > >Hi Oleksij, > > > >On Tue, Jul 14, 2015 at 08:40:47AM +0200, external.Oleksij.Rempel wrote: > >>Hi Dmitry, > >> > >>On 13.07.2015 19:07, Dmitry Torokhov wrote: > >>>On Mon, Jul 13, 2015 at 02:49:38PM +0200, Dirk Behme wrote: > >>>>From: Oleksij Rempel > >>>> > >>>>If zforce is not ready to process the interrupt, the touchscreen will > >>>>be lost forever. Make sure we enable the interrupt only if processing > >>>>is ready. > >>>> > >>>>Signed-off-by: Oleksij Rempel > >>>>Signed-off-by: Dirk Behme > >>>>--- > >>>> drivers/input/touchscreen/zforce_ts.c | 7 ++++++- > >>>> 1 file changed, 6 insertions(+), 1 deletion(-) > >>>> > >>>>diff --git a/drivers/input/touchscreen/zforce_ts.c b/drivers/input/touchscreen/zforce_ts.c > >>>>index 19dc297..a1889e5 100644 > >>>>--- a/drivers/input/touchscreen/zforce_ts.c > >>>>+++ b/drivers/input/touchscreen/zforce_ts.c > >>>>@@ -22,6 +22,7 @@ > >>>> #include > >>>> #include > >>>> #include > >>>>+#include > >>>> #include > >>>> #include > >>>> #include > >>>>@@ -741,6 +742,7 @@ static int zforce_probe(struct i2c_client *client, > >>>> struct zforce_ts *ts; > >>>> struct input_dev *input_dev; > >>>> int ret; > >>>>+ unsigned int irq; > >>>> if (!pdata) { > >>>> pdata = zforce_parse_dt(&client->dev); > >>>>@@ -835,6 +837,7 @@ static int zforce_probe(struct i2c_client *client, > >>>> init_completion(&ts->command_done); > >>>>+ irq = client->irq; > >>>> /* > >>>> * The zforce pulls the interrupt low when it has data ready. > >>>> * After it is triggered the isr thread runs until all the available > >>>>@@ -842,7 +845,8 @@ static int zforce_probe(struct i2c_client *client, > >>>> * Therefore we can trigger the interrupt anytime it is low and do > >>>> * not need to limit it to the interrupt edge. > >>>> */ > >>>>- ret = devm_request_threaded_irq(&client->dev, client->irq, > >>>>+ irq_set_status_flags(irq, IRQ_NOAUTOEN); > >>>Instead of playing with the flags should we simply request irq after we > >>>release the reset pin? > >>Because we should be able to process the interrupt. If i put > >>request_irq after reset, some times the interrupt can be missed. > >OK, I see that enabling after reset is racy. But I am still confused why > >having IRQ enabled while reste pin is asserted results in lost > >touchscreen. Can you walk me through the sequence of events? > > > >Thanks. > Mostly it will fail if zforce attached over SerDes > (Serializer/Deserializer). If we register IRQ after release of reset > pin, SerDes will get irq just before it has irq handler. In this > case irq will be lost, which means, not BOOT event will be passed to > the zforce. Yes, I agreed that requesting interrupt after releasing reset pin is not a good idea. But what is the issue with the original code that requests interrupt first (and enables it) and then releases the reset pin? Thanks. -- Dmitry