From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-path: Received: from mail-pg0-f65.google.com ([74.125.83.65]:36236 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750995AbdLDXwH (ORCPT ); Mon, 4 Dec 2017 18:52:07 -0500 Received: by mail-pg0-f65.google.com with SMTP id k134so9383036pga.3 for ; Mon, 04 Dec 2017 15:52:07 -0800 (PST) Date: Mon, 4 Dec 2017 15:52:05 -0800 From: Guenter Roeck To: Linus Walleij Cc: Jean Delvare , linux-hwmon@vger.kernel.org Subject: Re: [PATCH] hwmon: Deal with errors from the thermal subsystem Message-ID: <20171204235205.GA3396@roeck-us.net> References: <20171204222029.11956-1-linus.walleij@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171204222029.11956-1-linus.walleij@linaro.org> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org On Mon, Dec 04, 2017 at 11:20:29PM +0100, Linus Walleij wrote: > If the thermal subsystem returne -EPROBE_DEFER or any other error > when hwmon calls devm_thermal_zone_of_sensor_register(), this is > silently ignored. > > I ran into this with an incorrectly defined thermal zone, making > it non-existing and thus this call failed with -EPROBE_DEFER > assuming it would appear later. The sensor was still added > which is incorrect: sensors must strictly be added after the > thermal zones, so deferred probe must be respected. > > Signed-off-by: Linus Walleij > --- > drivers/hwmon/hwmon.c | 17 +++++++++++++---- > 1 file changed, 13 insertions(+), 4 deletions(-) > > diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c > index c9790e2c3440..6d1cb6b47490 100644 > --- a/drivers/hwmon/hwmon.c > +++ b/drivers/hwmon/hwmon.c > @@ -143,6 +143,7 @@ static int hwmon_thermal_add_sensor(struct device *dev, > struct hwmon_device *hwdev, int index) > { > struct hwmon_thermal_data *tdata; > + struct thermal_zone_device *tzd; > > tdata = devm_kzalloc(dev, sizeof(*tdata), GFP_KERNEL); > if (!tdata) > @@ -151,8 +152,10 @@ static int hwmon_thermal_add_sensor(struct device *dev, > tdata->hwdev = hwdev; > tdata->index = index; > > - devm_thermal_zone_of_sensor_register(&hwdev->dev, index, tdata, > - &hwmon_thermal_ops); > + tzd = devm_thermal_zone_of_sensor_register(&hwdev->dev, index, tdata, > + &hwmon_thermal_ops); > + if (IS_ERR(tzd)) > + return PTR_ERR(tzd); This won't work because devm_thermal_zone_of_sensor_register() returns -ENODEV if CONFIG_THERMAL_OF is disabled. We'll have to check for -EPROBE_DEFER and only return this specific error, but ignore all others. Thanks, Guenter > > return 0; > } > @@ -621,14 +624,20 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata, > if (!chip->ops->is_visible(drvdata, hwmon_temp, > hwmon_temp_input, j)) > continue; > - if (info[i]->config[j] & HWMON_T_INPUT) > - hwmon_thermal_add_sensor(dev, hwdev, j); > + if (info[i]->config[j] & HWMON_T_INPUT) { > + err = hwmon_thermal_add_sensor(dev, > + hwdev, j); > + if (err) > + goto free_device; > + } > } > } > } > > return hdev; > > +free_device: > + device_unregister(hdev); > free_hwmon: > kfree(hwdev); > ida_remove: > -- > 2.14.3 >