From nobody Thu Nov 28 21:49:07 2024 Received: from mail.manjaro.org (mail.manjaro.org [116.203.91.91]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BD71154454; Sat, 28 Sep 2024 04:13:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=116.203.91.91 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727496789; cv=none; b=mgNM5rALO3vFHGkVIsv1aJAVL4sWwy96fTRl1HPWQaUJ8eYsj6YbEfyHLmfLpqdCuYnrhXqSQUODXi5zQ9UO/tGs3CnUXyuvd4+wbYu4pl8bztQO/Mr7Ol/dxqFemf6EB8Vnis1QiDiNuTL41jhFRkbrZXda8Tu6PjhNcB3hUzM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727496789; c=relaxed/simple; bh=T4b5SCDbPtpznM3ly/UqgYB98QDVOVTAORg7GBHsgrI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZPTrS5Wc/3/H2RsExG1IrTonDEaMkNMbWRr4F7c8/LYpSH8PeYRSI3cooDFrkfBs1ZZ+mjyAKzkfPGYdidLs1GnQIVN/WBPt7mb9xCdX3+QGQLZRKjBrtAbq7BvcvnIBXasPCHcvd9FV2CfUdbpEIXKk09QIZORX4xpzhE/pSlA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org; spf=pass smtp.mailfrom=manjaro.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b=y2WoFxeF; arc=none smtp.client-ip=116.203.91.91 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=manjaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=manjaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=manjaro.org header.i=@manjaro.org header.b="y2WoFxeF" From: Dragan Simic DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=manjaro.org; s=2021; t=1727496780; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rKsTa/7rhm4a+RlN32Byj4tfrxf7+of7JzY7hJesRZ4=; b=y2WoFxeFfI2AKDIiPU6N0JB5zuc5QehUTZ35W2W1yLQNoFk7BdxJHHjy/ylXFRmZVttB4X ZMCfcuC9tqWEg9nbfEoY6DHtRp5Ogbe3l8hteoNlQEhGmvXIpuwSvO5S+ybexoC0AwkFf6 I6aMHf4TX8kNHavMvxzIGLlPgnXi5z1twYr6xRDGnNBDwv27cRbUgJK9jxxoZMuRxOR1fu l7tmbTxqoZ491jQRH+lEdmqG/4rKPIEsnFcT7+58fUssip0THFtN38ptRHWgBhdWW9NXpl 8F++KnEbrpMk0/uO5jGrIgYvNAhfDUQYV6myNXHG/YstnNPWNgiIYdmUMvPrVg== To: linux-spi@vger.kernel.org, linux-rockchip@lists.infradead.org Cc: broonie@kernel.org, heiko@sntech.de, gregkh@linuxfoundation.org, rafael@kernel.org, oss@helene.moe, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 4/5] driver core: Add device probe log helper dev_warn_probe() Date: Sat, 28 Sep 2024 06:12:48 +0200 Message-Id: <2fd9a60e0efe906dc7a203cd652c8d0b7f932470.1727496560.git.dsimic@manjaro.org> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Authentication-Results: ORIGINATING; auth=pass smtp.auth=dsimic@manjaro.org smtp.mailfrom=dsimic@manjaro.org Content-Type: text/plain; charset="utf-8" Some drivers can still provide their functionality to a certain extent even some of their resource acquisitions eventually fail. In such cases, emitti= ng errors isn't the desired action, but warnings should be emitted instead. To solve this, introduce dev_warn_probe() as a new device probe log helper, which behaves identically as the already existing dev_err_probe(), while it produces warnings instead of errors. The intended use is with the resources that are actually optional for a particular driver. While there, copyedit the kerneldoc for dev_err_probe() a bit, to simplify its wording a bit, and reuse it as the kerneldoc for dev_warn_probe(), with the necessary wording adjustments, of course. Signed-off-by: Dragan Simic --- drivers/base/core.c | 110 ++++++++++++++++++++++++++++--------- include/linux/dev_printk.h | 1 + 2 files changed, 84 insertions(+), 27 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 8c0733d3aad8..a4592b7ffa5d 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -4982,71 +4982,127 @@ define_dev_printk_level(_dev_info, KERN_INFO); =20 #endif =20 +static int dev_probe_failed(const struct device *dev, int err, bool fatal, + const char *fmt, va_list args) +{ + struct va_format vaf; + + vaf.fmt =3D fmt; + vaf.va =3D &args; + + switch (err) { + case -EPROBE_DEFER: + device_set_deferred_probe_reason(dev, &vaf); + dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf); + break; + + case -ENOMEM: + /* Don't print anything on -ENOMEM, there's already enough output */ + break; + + default: + /* Log fatal final failures as errors, otherwise produce warnings */ + if (fatal) + dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf); + else + dev_warn(dev, "error %pe: %pV", ERR_PTR(err), &vaf); + break; + } + + return err; +} + /** * dev_err_probe - probe error check and log helper * @dev: the pointer to the struct device * @err: error value to test * @fmt: printf-style format string * @...: arguments as specified in the format string * * This helper implements common pattern present in probe functions for er= ror * checking: print debug or error message depending if the error value is * -EPROBE_DEFER and propagate error upwards. * In case of -EPROBE_DEFER it sets also defer probe reason, which can be * checked later by reading devices_deferred debugfs attribute. - * It replaces code sequence:: + * It replaces the following code sequence:: * * if (err !=3D -EPROBE_DEFER) * dev_err(dev, ...); * else * dev_dbg(dev, ...); * return err; * * with:: * * return dev_err_probe(dev, err, ...); * - * Using this helper in your probe function is totally fine even if @err is - * known to never be -EPROBE_DEFER. + * Using this helper in your probe function is totally fine even if @err + * is known to never be -EPROBE_DEFER. * The benefit compared to a normal dev_err() is the standardized format - * of the error code, it being emitted symbolically (i.e. you get "EAGAIN" - * instead of "-35") and the fact that the error code is returned which al= lows - * more compact error paths. + * of the error code, which is emitted symbolically (i.e. you get "EAGAIN" + * instead of "-35"), and having the error code returned allows more + * compact error paths. * * Returns @err. */ int dev_err_probe(const struct device *dev, int err, const char *fmt, ...) { - struct va_format vaf; va_list args; =20 va_start(args, fmt); - vaf.fmt =3D fmt; - vaf.va =3D &args; =20 - switch (err) { - case -EPROBE_DEFER: - device_set_deferred_probe_reason(dev, &vaf); - dev_dbg(dev, "error %pe: %pV", ERR_PTR(err), &vaf); - break; + /* Use dev_err() for logging when err doesn't equal -EPROBE_DEFER */ + dev_probe_failed(dev, err, true, fmt, args); =20 - case -ENOMEM: - /* - * We don't print anything on -ENOMEM, there is already enough - * output. - */ - break; + va_end(args); +} +EXPORT_SYMBOL_GPL(dev_err_probe); =20 - default: - dev_err(dev, "error %pe: %pV", ERR_PTR(err), &vaf); - break; - } +/** + * dev_warn_probe - probe error check and log helper + * @dev: the pointer to the struct device + * @err: error value to test + * @fmt: printf-style format string + * @...: arguments as specified in the format string + * + * This helper implements common pattern present in probe functions for er= ror + * checking: print debug or warning message depending if the error value is + * -EPROBE_DEFER and propagate error upwards. + * In case of -EPROBE_DEFER it sets also defer probe reason, which can be + * checked later by reading devices_deferred debugfs attribute. + * It replaces the following code sequence:: + * + * if (err !=3D -EPROBE_DEFER) + * dev_warn(dev, ...); + * else + * dev_dbg(dev, ...); + * return err; + * + * with:: + * + * return dev_warn_probe(dev, err, ...); + * + * Using this helper in your probe function is totally fine even if @err + * is known to never be -EPROBE_DEFER. + * The benefit compared to a normal dev_warn() is the standardized format + * of the error code, which is emitted symbolically (i.e. you get "EAGAIN" + * instead of "-35"), and having the error code returned allows more + * compact error paths. + * + * Returns @err. + */ +int dev_warn_probe(const struct device *dev, int err, const char *fmt, ...) +{ + va_list args; =20 - va_end(args); + va_start(args, fmt); =20 - return err; + /* Use dev_warn() for logging when err doesn't equal -EPROBE_DEFER */ + dev_probe_failed(dev, err, false, fmt, args); + + va_end(args); } -EXPORT_SYMBOL_GPL(dev_err_probe); +EXPORT_SYMBOL_GPL(dev_warn_probe); =20 static inline bool fwnode_is_primary(struct fwnode_handle *fwnode) { diff --git a/include/linux/dev_printk.h b/include/linux/dev_printk.h index ca32b5bb28eb..eb2094e43050 100644 --- a/include/linux/dev_printk.h +++ b/include/linux/dev_printk.h @@ -276,6 +276,7 @@ do { \ dev_driver_string(dev), dev_name(dev), ## arg) =20 __printf(3, 4) int dev_err_probe(const struct device *dev, int err, const = char *fmt, ...); +__printf(3, 4) int dev_warn_probe(const struct device *dev, int err, const= char *fmt, ...); =20 /* Simple helper for dev_err_probe() when ERR_PTR() is to be returned. */ #define dev_err_ptr_probe(dev, ___err, fmt, ...) \