From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83715448B83 for ; Wed, 29 Jul 2026 09:46:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785318416; cv=none; b=cYGP5J+76jEyrfp0aSb7m1HW5jcbXmExOIgVYgdqThg+4TBI2otVoaZEHSyws5ISeXzvq4qQfySzfLC9pPkA3CF95zwhsHSL/bsQo3wSgNNw17FwQP94NN0ebAlLXOdVHnf8IIAaVVre8cDE15uy+Lxu5FXFxH7x9DRsfoqo5KQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785318416; c=relaxed/simple; bh=Gnhgiowt9LluQfmO7fvURZDudreaF+tkioAotKAsBh4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KAfpAVsGXZC9zei4HCqqiWhvN/yWcj4GhZUUktTfMuw0+Q2zz8liHAIKNpUb1TL/FbouNlESZAtJaluuXZ+vDfaTkLe3FlD/bTqdJvKtA8r1MClr4zUrQnv869Vx8ctc9EhaVeiXOcN+TUyoXQ6RX4/14F+Xc8G0jqM9JpZWpYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=heMOn96s; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="heMOn96s" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 276891F00A3E; Wed, 29 Jul 2026 09:46:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785318415; bh=puSaZwdrL0CfZKzSHm8CBYNIcQwIgp+QBt1jxR269dw=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=heMOn96sQ5v7g6iNW0jceXrWd/ZRoP9ZDbxRytl1+Kh77TWiArxZeP3m0IWcpdwc4 HLIIOaJkc2f2LR1IPcDaPmng3etjA/Q3NsfDm3Teg7n59OzZCuL2NTg6USRjMi8x3U i169pUplP5CDJm3ELLs6dBCvjEAqS7z55tplKw/uXvy/gz1pCQEjvueMM8wbgdoQiU y2M7AAWNkE0CjQSU8aYwOxxX/Mx9vUYrGFmSxadbogizcGhqWY5N0bvPoE2tCY4Yth a5A7uCMmLy6p+4uInFru3dI1yJXsFT/Qv2UO3UQuRF+Vs41bbzey6KVcHCgFFtVAYc SZKbkDXjLWUkw== From: srini@kernel.org To: gregkh@linuxfoundation.org Cc: linux-kernel@vger.kernel.org, Bartosz Golaszewski , Loic Poulain , Srinivas Kandagatla Subject: [PATCH 02/14] nvmem: return -EOPNOTSUPP to in-kernel users on missing callbacks Date: Wed, 29 Jul 2026 10:46:35 +0100 Message-ID: <20260729094647.111468-3-srini@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260729094647.111468-1-srini@kernel.org> References: <20260729094647.111468-1-srini@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Bartosz Golaszewski __nvmem_reg_read/write() currently return -EINVAL if the relevant callback is not present. User-space helpers again check the presence of the callbacks to see if they should return -EPERM. Ahead of adding SRCU synchronization: change the error code returned to in-kernel users to -EOPNOTSUPP which is more indicative of the actual reason for the failure. Remove the checks from the sysfs attribute callbacks as these are not visible without the required callbacks. Signed-off-by: Bartosz Golaszewski Tested-by: Loic Poulain Signed-off-by: Srinivas Kandagatla --- drivers/nvmem/core.c | 37 +++++++++++++++++++------------------ 1 file changed, 19 insertions(+), 18 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 703f760ad35e..ea17374209ba 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -55,10 +55,10 @@ static BLOCKING_NOTIFIER_HEAD(nvmem_notifier); static int __nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset, void *val, size_t bytes) { - if (nvmem->reg_read) - return nvmem->reg_read(nvmem->priv, offset, val, bytes); + if (!nvmem->reg_read) + return -EOPNOTSUPP; - return -EINVAL; + return nvmem->reg_read(nvmem->priv, offset, val, bytes); } static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, @@ -66,14 +66,14 @@ static int __nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset, { int ret; - if (nvmem->reg_write) { - gpiod_set_value_cansleep(nvmem->wp_gpio, 0); - ret = nvmem->reg_write(nvmem->priv, offset, val, bytes); - gpiod_set_value_cansleep(nvmem->wp_gpio, 1); - return ret; - } + if (!nvmem->reg_write) + return -EOPNOTSUPP; + + gpiod_set_value_cansleep(nvmem->wp_gpio, 0); + ret = nvmem->reg_write(nvmem->priv, offset, val, bytes); + gpiod_set_value_cansleep(nvmem->wp_gpio, 1); - return -EINVAL; + return ret; } static int nvmem_access_with_keepouts(struct nvmem_device *nvmem, @@ -231,13 +231,12 @@ static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, count = round_down(count, nvmem->word_size); - if (!nvmem->reg_read) - return -EPERM; - rc = nvmem_reg_read(nvmem, pos, buf, count); - - if (rc) + if (rc) { + if (rc == -EOPNOTSUPP) + return -EPERM; return rc; + } return count; } @@ -264,13 +263,15 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, count = round_down(count, nvmem->word_size); - if (!nvmem->reg_write || nvmem->read_only) + if (nvmem->read_only) return -EPERM; rc = nvmem_reg_write(nvmem, pos, buf, count); - - if (rc) + if (rc) { + if (rc == -EOPNOTSUPP) + return -EPERM; return rc; + } return count; } -- 2.53.0