From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 085D0C43460 for ; Wed, 7 Apr 2021 06:16:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C8FF6613C6 for ; Wed, 7 Apr 2021 06:16:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345517AbhDGGQe (ORCPT ); Wed, 7 Apr 2021 02:16:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239344AbhDGGQd (ORCPT ); Wed, 7 Apr 2021 02:16:33 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 65637C061756 for ; Tue, 6 Apr 2021 23:16:24 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lU1UC-0005bW-LU; Wed, 07 Apr 2021 08:16:20 +0200 Received: from ukl by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lU1UC-0004OE-31; Wed, 07 Apr 2021 08:16:20 +0200 Date: Wed, 7 Apr 2021 08:16:19 +0200 From: Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= To: Clemens Gruber Cc: linux-pwm@vger.kernel.org, Thierry Reding , Sven Van Asbroeck , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v7 8/8] pwm: pca9685: Add error messages for failed regmap calls Message-ID: <20210407061619.fl6ffos6csvgtnjh@pengutronix.de> References: <20210406164140.81423-1-clemens.gruber@pqgruber.com> <20210406164140.81423-8-clemens.gruber@pqgruber.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="vfnjmoawnycporzw" Content-Disposition: inline In-Reply-To: <20210406164140.81423-8-clemens.gruber@pqgruber.com> X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ukl@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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --vfnjmoawnycporzw Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 06, 2021 at 06:41:40PM +0200, Clemens Gruber wrote: > Regmap operations can fail if the underlying subsystem is not working > properly (e.g. hogged I2C bus, etc.) > As this is useful information for the user, print an error message if it > happens. > Let probe fail if the first regmap_read or the first regmap_write fails. >=20 > Signed-off-by: Clemens Gruber > --- > Changes since v6: > - Rebased >=20 > drivers/pwm/pwm-pca9685.c | 83 ++++++++++++++++++++++++++++----------- > 1 file changed, 59 insertions(+), 24 deletions(-) >=20 > diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c > index cf0c98e4ef44..8a4993882b40 100644 > --- a/drivers/pwm/pwm-pca9685.c > +++ b/drivers/pwm/pwm-pca9685.c > @@ -107,6 +107,30 @@ static bool pca9685_prescaler_can_change(struct pca9= 685 *pca, int channel) > return test_bit(channel, pca->pwms_enabled); > } > =20 > +static int pca9685_read_reg(struct pca9685 *pca, unsigned int reg, unsig= ned int *val) > +{ > + struct device *dev =3D pca->chip.dev; > + int err; > + > + err =3D regmap_read(pca->regmap, reg, val); > + if (err !=3D 0) > + dev_err(dev, "regmap_read of register 0x%x failed: %d\n", reg, err); Please use %pe to emit the error code instead of %d. > + > + return err; > +} > + > +static int pca9685_write_reg(struct pca9685 *pca, unsigned int reg, unsi= gned int val) > +{ > + struct device *dev =3D pca->chip.dev; > + int err; > + > + err =3D regmap_write(pca->regmap, reg, val); > + if (err !=3D 0) > + dev_err(dev, "regmap_write to register 0x%x failed: %d\n", reg, err); > + > + return err; > +} > + > /* Helper function to set the duty cycle ratio to duty/4096 (e.g. duty= =3D2048 -> 50%) */ > static void pca9685_pwm_set_duty(struct pca9685 *pca, int channel, unsig= ned int duty) > { > @@ -115,12 +139,12 @@ static void pca9685_pwm_set_duty(struct pca9685 *pc= a, int channel, unsigned int > =20 > if (duty =3D=3D 0) { > /* Set the full OFF bit, which has the highest precedence */ > - regmap_write(pca->regmap, REG_OFF_H(channel), LED_FULL); > + pca9685_write_reg(pca, REG_OFF_H(channel), LED_FULL); You didn't check all return codes? How did you select the calls to check? Best regards Uwe --=20 Pengutronix e.K. | Uwe Kleine-K=F6nig | Industrial Linux Solutions | https://www.pengutronix.de/ | --vfnjmoawnycporzw Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEfnIqFpAYrP8+dKQLwfwUeK3K7AkFAmBtTjEACgkQwfwUeK3K 7AmlpAf/Ys9OlGLMDV++TA9VDwM/Ywp0P7HPN+Pw/FaEO5wvTM9HBvACUwWOpBV7 iX50S3rqBwBpi4oy0eOEmKVibWWKwIIbLdVqq9Emaccl742KZ2Gt4ItW4qdKHkw/ q8hPbEBYLB5ZdgdCOnsiOj75nWcwoOrCH1d8szRAONN7fuNeV20ESF7FcurS44Xz 2UD+MyEZWui9deKSNE6JhzEWLYJQwtyhba0/bqD0++rhp4spKVrTb7df3YRi6EFv bJvMAahRP8I2FItnzsCmyCbrFkkhWnJL062wuMC745ZrCXTzp/1bNd4wXN3P27Dt VuYwFFqn/MFPgpnXX07s7Jk1QPTwCQ== =Gk6O -----END PGP SIGNATURE----- --vfnjmoawnycporzw--