From: Sebastian Reichel <sre@kernel.org>
To: "H. Nikolaus Schaller" <hns@goldelico.com>
Cc: "Dmitry Torokhov" <dmitry.torokhov@gmail.com>,
"Mark Rutland" <mark.rutland@arm.com>,
"Benoît Cousson" <bcousson@baylibre.com>,
"Tony Lindgren" <tony@atomide.com>,
"Russell King" <linux@armlinux.org.uk>,
"Arnd Bergmann" <arnd@arndb.de>,
"Michael Welling" <mwelling@ieee.org>,
"Mika Penttilä" <mika.penttila@nextfour.com>,
"Javier Martinez Canillas" <javier@osg.samsung.com>,
"Igor Grinberg" <grinberg@compulab.co.il>,
"Andrew F. Davis" <afd@ti.com>, "Mark Brown" <broonie@kernel.org>,
"Jonathan Cameron" <jic23@kernel.org>,
"Rob Herring" <robh+dt@kernel.org>,
"Alexander Stein" <alexander.stein@systec-electronic.com>,
"Eric Engestrom" <eric@engestrom.ch>,
"Hans de Goede" <hdegoede@redhat.com>,
"Benjamin Tissoires" <benjamin.tissoires@redhat.com>,
"Petr Cvek" <petr.cvek@tul.cz>,
"Mauro Carvalho Chehab" <mchehab@kernel.org>,
"Hans Verkuil" <hans.verkuil@cisco.com>,
"Nick Dyer" <nick@shmanahar.org>,
"Siebren Vroegindeweij" <siebren.vroegindeweij@hotmail.com>,
"Michel Verlaan" <michel.verl@gmail.com>,
linux-input@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org,
letux-kernel@openphoenux.org, linux-iio@vger.kernel.org,
kernel@pyra-handheld.com,
"Aaro Koskinen" <aaro.koskinen@nokia.com>,
"Pali Rohár" <pali.rohar@gmail.com>,
"Pavel Machek" <pavel@ucw.cz>,
"Andrey Gelman" <andrey.gelman@compulab.co.il>,
"Haibo Chen" <haibo.chen@freescale.com>
Subject: Re: [PATCH v9 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation
Date: Sun, 19 Feb 2017 00:44:22 +0100 [thread overview]
Message-ID: <20170218234422.vza3toc3bphixsdn@earth> (raw)
In-Reply-To: <95E59EB0-6F96-40BB-B74C-9CD56DDD7783@goldelico.com>
[-- Attachment #1: Type: text/plain, Size: 5014 bytes --]
Hi,
On Sat, Feb 18, 2017 at 12:33:34PM +0100, H. Nikolaus Schaller wrote:
> Hi Sebastian,
>
> > Am 18.02.2017 um 04:22 schrieb Sebastian Reichel <sre@kernel.org>:
> >
> > Hi,
> >
> > On Fri, Feb 17, 2017 at 12:40:41PM -0800, Dmitry Torokhov wrote:
> >>> AFAIK there is no mainline board using the DT except ours (and the upcoming
> >>> OMAP5-Pyra), so we shouldn't care too much. If you prefer, you can remove this
> >>> compatibility property. We don't need it for our devices.
> >
> > $ cd linux.git/arch
> > $ git grep -l tsc2004
> > arm/boot/dts/imx6qdl-nit6xlite.dtsi
> > arm/boot/dts/imx7d-nitrogen7.dts
> > arm/boot/dts/logicpd-torpedo-37xx-devkit.dts
> > arm/boot/dts/omap4-var-som-om44.dtsi
> > $ git grep -l tsc2005
> > arm/boot/dts/omap3-n900.dts
>
> Those are not relevant since tsc2004/5 and tsc2007 are independent drivers and don't
> share code.
Yes, I'm aware.
> Hence the N900 is not influenced by this patch series.
> If it has a similar issue, it should be fixed of course.
Right. I added them to see every board affect by the patch suggested
by me in my last paragraph.
> > $ git grep -l tsc2007
> > arm/boot/dts/imx28-tx28.dts
> > arm/boot/dts/imx35-eukrea-cpuimx35.dtsi
> > arm/boot/dts/imx51-eukrea-cpuimx51.dtsi
> > arm/boot/dts/imx53-tx53-x03x.dts
> > arm/boot/dts/imx6qdl-tx6.dtsi
> > arm/boot/dts/imx6ul-tx6ul.dtsi
> > arm/boot/dts/omap3-gta04.dtsi
> > sh/boards/mach-ecovec24/setup.c
>
> Sorry, I was a little imprecise here, because I looked for the min/max properties.
> Of course, the imx devices use the tsc2007 as well.
>
> Maybe we should edit all these DTS and set the "ti,report-resistance" property
> by default. Then, no user should notice a difference.
I suggest to create a patch without the report-reistance stuff and
add it early after the merge window and see what happens. If no
users notices anything the change is not an ABI break from kernel's
PoV.
> Is any user/maintainer of these devices following this discussion and can comment?
>
> >
> >> You seem to be treating DT data as something very fluid, which is wrong.
> >> You need to treat it as a firmware, unlikely to change once device is
> >> shipped. Unlike legacy platform data, the fact that DTS files are not
> >> present in mainline does not mean that we can ignore such users and
> >> change behavior at will.
> >>
> >> That said, if driver behavior is out of line from the subsystem
> >> expectations, we need to fix it.
> >>
> >>
> >>> That the function name is wrong is a second issue and this double negation might
> >>> confuse a litte.
> >>>
> >>> Please test on a real device if the patched driver reports pressure now (unless
> >>> ti,report-resistance is specified).
> >>
> >> I unfortunately can not test this driver as I do not have the hardware.
> >> So all my observations are from code and data sheets.
> >>
> >> That said, what is the values emitted as ABS_PRESSURE when finger is not
> >> touching the device, barely touching the device, or pressing firmly?
> >> It seems that between TSC2007, TSC2004, TSC2005, and ADS7846, we have
> >> confusion as to what is being reported.
> >
> > As far as I can see all calculate Rtouch and ADS7846 reports
> > (Rmax - Rtouch), which looks sensible.
>
> I don't see where this subtraction from Rmax takes place for the tsc2007:
>
> http://lxr.free-electrons.com/source/drivers/input/touchscreen/tsc2007.c#L131
sorry if I wrote this ambiguous, let me split my sentence
1. tsc200x & ads7846 calculate Rtouch
2. ads7846 reports Rmax - Rtouch
(3. tsc200x does not, it reports Rtouch instead)
4. ads7846 behaviour looks sensible to me
> >> I am adding a few more folks to the CC so we can try and soft this out.
> >> Sebastian, Pali, Pavel, any input here?
> >
> > I think tsc200x works, since usually userspace is Xorg and I think
> > it only cares for x/y coordinates + boolean pressure. Since
> > no-pressure is correctly reported as 0, everything works as
> > expected.
>
> No pressure is usually treated as a special case in these drivers,
> so reduction to "boolean" in user-space works well by accident and
> might still hide a bug.
That's what I assumed.
Btw. how did you notice that tsc2007 sends "inverted" pressure values?
Just in evtest or in some non-development application? (Just asking because
the behavour obviously changes at least for that usecase)
> > I currently don't have X running on my N900 due some
> > omapdrm bug, so I can't test this, sorry.
>
> I usually look with evtest if ABS_PRESSURE is monotonic.
That would not have helped to check if X handles the touchscreen in
a boolean way. I can provide some N900 evtest data, though (tomorrow,
I don't have my dev N900 with me at the moment).
> > I suggest to put the resistance vs pressure thing in its own patch,
> > that also fixes tsc200x-core and merge it to linux-next after the
> > merge window.
-- Sebastian
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next prev parent reply other threads:[~2017-02-18 23:44 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-28 14:53 [PATCH v9 0/8] drivers: touchscreen: tsc2007 and ads7846/tsc2046 improvements (use common touchscreen bindings, pre-calibration, spi fix and provide iio raw values) H. Nikolaus Schaller
2016-12-28 14:53 ` [PATCH v9 1/8] drivers:input:tsc2007: add new common binding names, pre-calibration, flipping and rotation H. Nikolaus Schaller
2017-01-09 17:43 ` Rob Herring
2017-01-28 19:33 ` Dmitry Torokhov
2017-01-28 21:44 ` H. Nikolaus Schaller
2017-02-17 20:40 ` Dmitry Torokhov
2017-02-18 3:22 ` Sebastian Reichel
2017-02-18 11:33 ` H. Nikolaus Schaller
2017-02-18 23:44 ` Sebastian Reichel [this message]
2017-02-19 12:07 ` H. Nikolaus Schaller
2017-02-19 20:15 ` Sebastian Reichel
2017-02-20 16:49 ` H. Nikolaus Schaller
2017-02-18 7:45 ` [Letux-kernel] " Andreas Kemnade
2017-02-18 9:15 ` Pavel Machek
2017-02-18 11:33 ` H. Nikolaus Schaller
2017-02-18 18:08 ` Pavel Machek
2017-02-18 19:17 ` H. Nikolaus Schaller
2017-02-18 22:54 ` Pavel Machek
2017-02-19 12:05 ` H. Nikolaus Schaller
2017-02-19 14:17 ` Pavel Machek
2017-02-19 17:04 ` H. Nikolaus Schaller
2017-02-19 17:15 ` Pavel Machek
2017-02-19 17:51 ` H. Nikolaus Schaller
2017-02-19 19:05 ` Pavel Machek
2017-02-19 19:31 ` H. Nikolaus Schaller
2017-02-19 20:57 ` Pavel Machek
2017-02-19 22:01 ` H. Nikolaus Schaller
2017-02-19 22:19 ` Pavel Machek
2017-02-20 16:50 ` H. Nikolaus Schaller
2017-02-20 19:29 ` Pavel Machek
2017-02-20 20:20 ` H. Nikolaus Schaller
2017-02-20 22:26 ` Petr Cvek
2017-02-21 8:29 ` H. Nikolaus Schaller
2017-02-19 22:29 ` [Letux-kernel] " Andreas Kemnade
2017-02-19 22:39 ` Pavel Machek
2017-02-20 16:50 ` H. Nikolaus Schaller
2017-02-20 19:32 ` Pavel Machek
2017-02-20 20:22 ` H. Nikolaus Schaller
2017-02-20 20:50 ` H. Nikolaus Schaller
2017-02-18 11:32 ` H. Nikolaus Schaller
2017-02-20 1:07 ` Dmitry Torokhov
2017-02-20 16:50 ` H. Nikolaus Schaller
2017-02-20 19:42 ` Pali Rohár
2017-02-20 20:35 ` H. Nikolaus Schaller
2017-02-20 21:07 ` Pali Rohár
2017-02-20 21:24 ` H. Nikolaus Schaller
2017-02-20 21:54 ` Pali Rohár
2017-02-21 6:42 ` H. Nikolaus Schaller
2017-02-21 8:53 ` Pali Rohár
2017-02-20 21:08 ` Pali Rohár
2017-02-20 21:27 ` H. Nikolaus Schaller
2017-02-20 21:50 ` Dmitry Torokhov
2017-02-20 22:21 ` Petr Cvek
2017-02-20 22:24 ` Dmitry Torokhov
2017-02-21 6:56 ` H. Nikolaus Schaller
2017-02-20 22:45 ` Pali Rohár
2017-02-21 6:36 ` H. Nikolaus Schaller
2017-02-21 9:09 ` Pali Rohár
2017-02-21 17:07 ` [Letux-kernel] " Andreas Kemnade
2017-02-20 22:04 ` Pali Rohár
2017-02-21 6:49 ` H. Nikolaus Schaller
2017-02-21 7:14 ` H. Nikolaus Schaller
2017-02-21 8:47 ` Pali Rohár
2017-02-21 8:57 ` [Letux-kernel] " Christ van Willegen
2017-02-21 11:07 ` Pavel Machek
2016-12-28 14:53 ` [PATCH v9 2/8] drivers:input:tsc2007: check for presence and power down tsc2007 during probe H. Nikolaus Schaller
2017-02-17 20:52 ` Dmitry Torokhov
2016-12-28 14:53 ` [PATCH v9 3/8] DT:omap3+tsc2007: use new common touchscreen bindings H. Nikolaus Schaller
2016-12-28 14:53 ` [PATCH v9 4/8] drivers:input:ads7846(+tsc2046): add new common binding names, pre-calibration and flipping H. Nikolaus Schaller
2016-12-28 14:53 ` [PATCH v9 5/8] dt-bindings: input: move ads7846 bindings to touchscreen subdirectory H. Nikolaus Schaller
2017-02-23 9:54 ` H. Nikolaus Schaller
2016-12-28 14:53 ` [PATCH v9 6/8] drivers:input:ads7846(+tsc2046): fix spi module table H. Nikolaus Schaller
2017-01-28 19:35 ` Dmitry Torokhov
2017-01-29 8:39 ` H. Nikolaus Schaller
2017-01-29 18:01 ` Dmitry Torokhov
2017-01-29 18:25 ` H. Nikolaus Schaller
2017-02-01 20:20 ` H. Nikolaus Schaller
2017-02-01 21:14 ` Javier Martinez Canillas
2017-02-01 22:28 ` Dmitry Torokhov
2017-02-01 22:50 ` Javier Martinez Canillas
2017-02-02 5:47 ` H. Nikolaus Schaller
2016-12-28 14:53 ` [PATCH v9 7/8] DT:omap3+ads7846: use new common touchscreen bindings H. Nikolaus Schaller
2016-12-28 14:53 ` [PATCH v9 8/8] drivers:input:tsc2007: add iio interface to read external ADC input and temperature H. Nikolaus Schaller
2016-12-30 20:36 ` Jonathan Cameron
2017-02-17 21:27 ` Dmitry Torokhov
2017-02-18 11:35 ` H. Nikolaus Schaller
2017-01-16 6:34 ` [PATCH v9 0/8] drivers: touchscreen: tsc2007 and ads7846/tsc2046 improvements (use common touchscreen bindings, pre-calibration, spi fix and provide iio raw values) H. Nikolaus Schaller
2017-01-21 13:08 ` Jonathan Cameron
2017-01-21 13:17 ` H. Nikolaus Schaller
2017-01-28 18:16 ` [Letux-kernel] " H. Nikolaus Schaller
2017-02-12 15:18 ` H. Nikolaus Schaller
2017-02-15 14:03 ` H. Nikolaus Schaller
2017-02-17 20:43 ` Dmitry Torokhov
2017-02-18 11:30 ` H. Nikolaus Schaller
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