From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756219Ab3DWNIW (ORCPT ); Tue, 23 Apr 2013 09:08:22 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:60542 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755760Ab3DWNIV (ORCPT ); Tue, 23 Apr 2013 09:08:21 -0400 Message-ID: <517687AB.1040309@pengutronix.de> Date: Tue, 23 Apr 2013 15:07:55 +0200 From: Marc Kleine-Budde User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130328 Thunderbird/17.0.5 MIME-Version: 1.0 To: Shawn Guo CC: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Andres Salomon , arm@kernel.org, John Stultz , Nicolas Ferre , "kernel@pengutronix.de" Subject: BUG: Re: [PATCH v2 3/3] clocksource: use clockevents_config_and_register() where possible References: <1357991406-22778-1-git-send-email-shawn.guo@linaro.org> <1357991406-22778-4-git-send-email-shawn.guo@linaro.org> In-Reply-To: <1357991406-22778-4-git-send-email-shawn.guo@linaro.org> X-Enigmail-Version: 1.5.1 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="----enig2EORJKSLMIDNQDJXULRLH" X-SA-Exim-Connect-IP: 2001:6f8:1178:4:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2EORJKSLMIDNQDJXULRLH Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: quoted-printable Hello, On 01/12/2013 12:50 PM, Shawn Guo wrote: > The clockevent core is able to figure out the best mult and shift, > calculate min_delta_ns and max_delta_ns, with the necessary info passed= > into clockevents_config_and_register(). Use this combined configure > and register function where possible to make the codes less error prone= > and gain some positive diff stat. >=20 > Signed-off-by: Shawn Guo > Cc: Andres Salomon > Cc: Nicolas Ferre > Acked-by: Maxime Ripard [...] I just bisected a timer problem down to this commit. > diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb= _clksrc.c > index 32cb929..8a61872 100644 > --- a/drivers/clocksource/tcb_clksrc.c > +++ b/drivers/clocksource/tcb_clksrc.c > @@ -157,7 +157,6 @@ static struct tc_clkevt_device clkevt =3D { > .name =3D "tc_clkevt", > .features =3D CLOCK_EVT_FEAT_PERIODIC > | CLOCK_EVT_FEAT_ONESHOT, > - .shift =3D 32, > /* Should be lower than at91rm9200's system timer */ > .rating =3D 125, > .set_next_event =3D tc_next_event, > @@ -196,13 +195,9 @@ static void __init setup_clkevents(struct atmel_tc= *tc, int clk32k_divisor_idx) > =20 > timer_clock =3D clk32k_divisor_idx; > =20 > - clkevt.clkevt.mult =3D div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shif= t); > - clkevt.clkevt.max_delta_ns > - =3D clockevent_delta2ns(0xffff, &clkevt.clkevt); > - clkevt.clkevt.min_delta_ns =3D clockevent_delta2ns(1, &clkevt.clkevt)= + 1; = ^^^^^^ With this patch, the "+ 1" gets lost, resulting in a different "min_delta_ns". good: setup_clkevents: shift=3D32 mult=3D140737 min=3D30518 max=3D1999976422 bad: setup_clkevents: shift=3D32 mult=3D140737 min=3D30517 max=3D1999976422 This leads to problems with schedule_delayed_work() with a delay of "1". These worksqueues seem to be hanging for several seconds. I'll send a RFC patch. > clkevt.clkevt.cpumask =3D cpumask_of(0); > =20 > - clockevents_register_device(&clkevt.clkevt); > + clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff); > =20 > setup_irq(irq, &tc_irqaction); > } >=20 Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | ------enig2EORJKSLMIDNQDJXULRLH Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlF2h64ACgkQjTAFq1RaXHOhSQCffo2ENeLddFYL+AWBlqoUx/Ou enwAnibh2SlS3gkSyPwHZFLi6mXOMdf3 =E61t -----END PGP SIGNATURE----- ------enig2EORJKSLMIDNQDJXULRLH--