Linux Input/HID development
 help / color / mirror / Atom feed
From: Stanislav Brabec <utx@penguin.cz>
To: Pavel Machek <pavel@ucw.cz>
Cc: dtor@mail.ru, linux-input@vger.kernel.org, rpurdie@rpsys.net,
	lenz@cs.wisc.edu, kernel list <linux-kernel@vger.kernel.org>,
	Dirk@Opfer-Online.de, arminlitzel@web.de,
	Cyril Hrubis <metan@ucw.cz>,
	thommycheck@gmail.com,
	linux-arm-kernel <linux-arm-kernel@lists.arm.linux.org.uk>,
	dbaryshkov@gmail.com, omegamoon@gmail.com,
	eric.miao@marvell.comCyril Hrubis <metan@ucw.cz>
Subject: Re: ads7846: clean up, fix pressure reporting
Date: Sun, 09 Aug 2009 12:21:33 +0200	[thread overview]
Message-ID: <1249813293.4334.24.camel@utx.utx.cz> (raw)
In-Reply-To: <20090807180941.GF1728@ucw.cz>

Pavel Machek wrote:
> Fix pressure reporting, and clean up debug prints.

Thanks.

I see much bigger problem with both the old driver and the new ads7846
driver (2.6.30): They are very noisy on my spitz. When you tap to one
place, keep stylus pressed and just read values, you get 20-200 pixels
long pointer motion trip each second.

According to Cyril Hrubiš, it is caused by the electrical noise that
originates in the LCD display. The driver needs to read data
synchronously with the LCD refresh. He already made the fix for collie
several years ago.

The pointer test application in the PROM diagnostic utility does not
seem to exhibit any noise.


________________________________________________________________________
Stanislav Brabec
http://www.penguin.cz/~utx/zaurus


-------------------------------------------------------------------
List admin: http://lists.arm.linux.org.uk/mailman/listinfo/linux-arm-kernel
FAQ:        http://www.arm.linux.org.uk/mailinglists/faq.php
Etiquette:  http://www.arm.linux.org.uk/mailinglists/etiquette.php

  reply	other threads:[~2009-08-09 10:21 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-08-07 18:09 ads7846: clean up, fix pressure reporting Pavel Machek
2009-08-09 10:21 ` Stanislav Brabec [this message]
2009-08-10 21:10   ` Richard Purdie
2009-08-09 10:51 ` Mark Brown
2009-08-09 10:54   ` Pavel Machek

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1249813293.4334.24.camel@utx.utx.cz \
    --to=utx@penguin.cz \
    --cc=Dirk@Opfer-Online.de \
    --cc=arminlitzel@web.de \
    --cc=dbaryshkov@gmail.com \
    --cc=dtor@mail.ru \
    --cc=eric.miao@marvell.comCyril \
    --cc=lenz@cs.wisc.edu \
    --cc=linux-arm-kernel@lists.arm.linux.org.uk \
    --cc=linux-input@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=metan@ucw.cz \
    --cc=omegamoon@gmail.com \
    --cc=pavel@ucw.cz \
    --cc=rpurdie@rpsys.net \
    --cc=thommycheck@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox