From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kalle Jokiniemi Subject: Re: [PATCH 1/1] input: ff-memless: Allow negative attack / fade ramps Date: Fri, 28 Aug 2015 17:41:12 +0300 Message-ID: <55E07308.6040007@jolla.com> References: <1440673422-12279-1-git-send-email-kalle.jokiniemi@jolla.com> <1440673422-12279-2-git-send-email-kalle.jokiniemi@jolla.com> <55E06A65.3060001@jolla.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from smtp64.ord1c.emailsrvr.com ([108.166.43.64]:60516 "EHLO smtp64.ord1c.emailsrvr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752106AbbH1OlO (ORCPT ); Fri, 28 Aug 2015 10:41:14 -0400 In-Reply-To: <55E06A65.3060001@jolla.com> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: dmitry.torokhov@gmail.com Cc: linux-input@vger.kernel.org Hi, On 28.08.2015 17:04, Kalle Jokiniemi wrote: > Hi, > > Please disregard this patch, the math doesn't really change with this. I > need to dig deeper what really was the issue, as I could see the > negative ramp not working. It seems the mis-interpretation of negative ramps not working was my personal user error of trying to do it with too short effects and FF_ENVELOPE_INTERVAL being 50ms. Sorry for the noise. - Kalle > > - Kalle > > On 27.08.2015 14:03, Kalle Jokiniemi wrote: >> Currently the ff-memless force feedback periodic effects can only >> have rising attack periods and declining fade periods. E.g. setting >> a attack ramp that starts high to lower to normal magnitude, will >> just cause the effect to rumble at high static speed for duration >> of the attack period and then abruptly lower back to normal >> magnitude instead of linearly declining the effect during attack >> phase. >> >> To fix this, a check has been added to see if the envelope_level >> of the attack or fade period is higher than default magnitude or >> vise versa, and then adjusting the difference value calculation >> accordingly. >> >> Signed-off-by: Kalle Jokiniemi >> --- >> drivers/input/ff-memless.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/input/ff-memless.c b/drivers/input/ff-memless.c >> index 0723e0d..487df7e 100644 >> --- a/drivers/input/ff-memless.c >> +++ b/drivers/input/ff-memless.c >> @@ -190,7 +190,10 @@ static int apply_envelope(struct ml_effect_state >> *state, int value, >> } else >> return value; >> >> - difference = abs(value) - envelope_level; >> + if (abs(value) >= envelope_level) >> + difference = abs(value) - envelope_level; >> + else >> + difference = -(envelope_level - abs(value)); >> >> pr_debug("difference = %d\n", difference); >> pr_debug("time_from_level = 0x%x\n", time_from_level); >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-input" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html