From: vigneshr@ti•com (Vignesh R)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 1/4] input: touchscreen: ti_am335x_tsc Interchange touchscreen and ADC steps
Date: Mon, 10 Nov 2014 16:16:22 +0530 [thread overview]
Message-ID: <5460977E.9060604@ti.com> (raw)
In-Reply-To: <20141107080033.GA6455@netboy>
On Friday 07 November 2014 01:30 PM, Richard Cochran wrote:
> On Fri, Nov 07, 2014 at 11:04:05AM +0530, Vignesh R wrote:
>>
>> Currently, there is too much noise in the TSC hardware that is being
>> removed by delta filtering.
>
> The so called "filter" was only programmed because the fifo entries
> were being mixed up. Sebastian fixed that.
>
>> I tested TSC unit by removing filtering
>> logic, the performance was not at all satisfactory. The cursor jumps
>> wayward and smooth circles cannot be drawn. Looks like delta filtering
>> cannot be removed as of now. May be I will try and address it in future.
>
> The "filter" code is nonsensical. It picks the two values in seqeunce
> that are closest to one and another. How is that supposed to work?
>
> Did you look at the "noise"? What kind of properties did you see?
>
> A median filter makes more sense. Or sort, remove outliers, and
> average. But choosing the two closest in series is silly.
I was able to implement median filter as you described and achieve
reliable performance. I will append that to this series of patches in v3.
Regards
Vignesh
>
> Thanks,
> Richard
>
next prev parent reply other threads:[~2014-11-10 10:46 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-10-27 11:08 [PATCH 0/4] Touchscreen performance related fixes Vignesh R
2014-10-27 11:08 ` [PATCH 1/4] input: touchscreen: ti_am335x_tsc Interchange touchscreen and ADC steps Vignesh R
2014-10-31 21:03 ` Hartmut Knaack
2014-11-07 5:48 ` Vignesh R
2014-11-06 14:19 ` Richard Cochran
2014-11-07 5:34 ` Vignesh R
2014-11-07 8:00 ` Richard Cochran
2014-11-10 10:46 ` Vignesh R [this message]
2014-11-07 10:17 ` Richard Cochran
2014-10-27 11:08 ` [PATCH 2/4] input: touchscreen: ti_am335x_tsc: Remove udelay in interrupt handler Vignesh R
2014-11-03 15:05 ` Lee Jones
2014-11-07 5:48 ` Vignesh R
2014-10-27 11:08 ` [PATCH 3/4] arm: boot: dts: am335x-evm: Make charge delay a DT parameter for tsc Vignesh R
2014-10-31 21:09 ` Hartmut Knaack
2014-11-07 5:48 ` Vignesh R
2014-10-27 11:08 ` [PATCH 4/4] input: touchscreen: ti_am335x_tsc: Use charge delay DT parameter Vignesh R
2014-10-27 17:34 ` [PATCH 0/4] Touchscreen performance related fixes Sebastian Andrzej Siewior
2014-10-27 19:02 ` Griffis, Brad
2014-11-03 12:17 ` Sebastian Andrzej Siewior
2014-11-04 11:44 ` Vignesh R
2014-11-04 12:37 ` Sebastian Andrzej Siewior
2014-11-05 12:08 ` Vignesh R
2014-11-17 12:18 ` Vignesh R
2014-11-03 18:09 ` Richard Cochran
2014-11-06 7:42 ` Vignesh R
2014-11-12 13:00 ` Johannes Pointner
2014-11-13 12:23 ` Vignesh R
2014-11-17 11:39 ` Vignesh R
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