linux-kernel - Re: [PATCH v4 0/6] Touchscreen performance related fixes

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Message-ID: <20141216153048.GA16981@localhost.localdomain>
Date:	Tue, 16 Dec 2014 16:30:48 +0100
From:	Richard Cochran <richardcochran@...il.com>
To:	Catalin Crenguta <catalin.crenguta@...il.com>
Cc:	"Griffis, Brad" <bgriffis@...com>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	Nicolae Rosia <nicolae.rosia@...il.com>,
	"R, Vignesh" <vigneshr@...com>, Rob Herring <robh+dt@...nel.org>,
	Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Benoit Cousson <bcousson@...libre.com>,
	Tony Lindgren <tony@...mide.com>,
	Russell King <linux@....linux.org.uk>,
	Jonathan Cameron <jic23@...nel.org>,
	Hartmut Knaack <knaack.h@....de>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Lee Jones <lee.jones@...aro.org>,
	Lars-Peter Clausen <lars@...afoo.de>,
	Peter Meerwald <pmeerw@...erw.net>,
	Samuel Ortiz <sameo@...ux.intel.com>,
	"Balbi, Felipe" <balbi@...com>,
	Sanjeev Sharma <sanjeev_sharma@...tor.com>,
	Paul Gortmaker <paul.gortmaker@...driver.com>,
	Jan Kardell <jan.kardell@...liq.com>,
	"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>,
	"linux-arm-kernel@...ts.infradead.org" 
	<linux-arm-kernel@...ts.infradead.org>,
	"linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
	"linux-input@...r.kernel.org" <linux-input@...r.kernel.org>
Subject: Re: [PATCH v4 0/6] Touchscreen performance related fixes

On Tue, Dec 16, 2014 at 10:31:47AM +0200, Catalin Crenguta wrote:
> 
> It seems that because the ribbon cable has both the analog and digital
> signals, the analog signals are affected by the digital ones (hence
> the touchscreen was working OK when the display was disabled). Putting
> decoupling capacitors on X+, X-, Y+, Y- reduces the noise and the
> false events disappear.

IOW, the root cause is a design flaw in the BB-View 4.3 Cape?

Thanks,
Richard
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