[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <y7xhfbiwkduo3lytb5gbukdu3yptx6uajtbngbspqbqkyt5dzo@gy62zoxwr6ah>
Date: Fri, 18 Jul 2025 21:37:08 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@....qualcomm.com>
To: Shivendra Pratap <shivendra.pratap@....qualcomm.com>
Cc: Bartosz Golaszewski <bartosz.golaszewski@...aro.org>,
Bjorn Andersson <andersson@...nel.org>,
Sebastian Reichel <sre@...nel.org>, Rob Herring <robh@...nel.org>,
Sudeep Holla <sudeep.holla@....com>,
Souvik Chakravarty <Souvik.Chakravarty@....com>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>, Andy Yan <andy.yan@...k-chips.com>,
Mark Rutland <mark.rutland@....com>,
Lorenzo Pieralisi <lpieralisi@...nel.org>,
Arnd Bergmann <arnd@...db.de>, Konrad Dybcio <konradybcio@...nel.org>,
cros-qcom-dts-watchers@...omium.org, Vinod Koul <vkoul@...nel.org>,
Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will@...nel.org>,
Florian Fainelli <florian.fainelli@...adcom.com>,
Mukesh Ojha <mukesh.ojha@....qualcomm.com>,
Stephen Boyd <swboyd@...omium.org>,
Andre Draszik <andre.draszik@...aro.org>, linux-pm@...r.kernel.org,
linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, linux-arm-msm@...r.kernel.org,
Elliot Berman <quic_eberman@...cinc.com>,
Srinivas Kandagatla <srini@...nel.org>
Subject: Re: [PATCH v11 1/8] power: reset: reboot-mode: Add device tree
node-based registration
On Thu, Jul 17, 2025 at 06:16:47PM +0530, Shivendra Pratap wrote:
> The reboot-mode driver does not have a strict requirement for
> device-based registration. It primarily uses the device's of_node
> to read mode-<cmd> properties and the device pointer for logging.
>
> Remove the dependency on struct device and introduce support for
> Device Tree (DT) node-based registration. This enables drivers
> that are not associated with a struct device to leverage the
> reboot-mode framework.
>
> Signed-off-by: Shivendra Pratap <shivendra.pratap@....qualcomm.com>
> ---
> drivers/power/reset/reboot-mode.c | 29 +++++++++++++++++++----------
> include/linux/reboot-mode.h | 2 +-
> 2 files changed, 20 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/power/reset/reboot-mode.c b/drivers/power/reset/reboot-mode.c
> index fba53f638da04655e756b5f8b7d2d666d1379535..0269ec55106472cf2f2b12bd65704dd0114bf4a3 100644
> --- a/drivers/power/reset/reboot-mode.c
> +++ b/drivers/power/reset/reboot-mode.c
> @@ -3,13 +3,17 @@
> * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
> */
>
> +#define pr_fmt(fmt) "reboot-mode: " fmt
> +
> #include <linux/device.h>
> #include <linux/init.h>
> #include <linux/kernel.h>
> +#include <linux/list.h>
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/reboot.h>
> #include <linux/reboot-mode.h>
> +#include <linux/slab.h>
>
> #define PREFIX "mode-"
>
> @@ -65,33 +69,35 @@ static int reboot_mode_notify(struct notifier_block *this,
> /**
> * reboot_mode_register - register a reboot mode driver
> * @reboot: reboot mode driver
> + * @np: Pointer to device tree node
> *
> * Returns: 0 on success or a negative error code on failure.
> */
> -int reboot_mode_register(struct reboot_mode_driver *reboot)
> +int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np)
> {
> struct mode_info *info;
> struct property *prop;
> - struct device_node *np = reboot->dev->of_node;
> size_t len = strlen(PREFIX);
> int ret;
>
> + if (!np)
> + return -EINVAL;
> +
> INIT_LIST_HEAD(&reboot->head);
>
> for_each_property_of_node(np, prop) {
> if (strncmp(prop->name, PREFIX, len))
> continue;
>
> - info = devm_kzalloc(reboot->dev, sizeof(*info), GFP_KERNEL);
> + info = kzalloc(sizeof(*info), GFP_KERNEL);
> if (!info) {
> ret = -ENOMEM;
> goto error;
> }
>
> if (of_property_read_u32(np, prop->name, &info->magic)) {
> - dev_err(reboot->dev, "reboot mode %s without magic number\n",
> - info->mode);
> - devm_kfree(reboot->dev, info);
> + pr_err("reboot mode %s without magic number\n", info->mode);
> + kfree(info);
> continue;
> }
>
> @@ -102,8 +108,7 @@ int reboot_mode_register(struct reboot_mode_driver *reboot)
> } else if (info->mode[0] == '\0') {
> kfree_const(info->mode);
> ret = -EINVAL;
> - dev_err(reboot->dev, "invalid mode name(%s): too short!\n",
> - prop->name);
> + pr_err("invalid mode name(%s): too short!\n", prop->name);
> goto error;
> }
>
> @@ -130,11 +135,15 @@ EXPORT_SYMBOL_GPL(reboot_mode_register);
> int reboot_mode_unregister(struct reboot_mode_driver *reboot)
> {
> struct mode_info *info;
> + struct mode_info *next;
>
> unregister_reboot_notifier(&reboot->reboot_notifier);
>
> - list_for_each_entry(info, &reboot->head, list)
> + list_for_each_entry_safe(info, next, &reboot->head, list) {
This feels liks a missing lock.
> kfree_const(info->mode);
> + list_del(&info->list);
list_del should come before kfree, otherwise it's possible to access
freed memory while traversing the list.
> + kfree(info);
> + }
>
> return 0;
> }
> @@ -162,7 +171,7 @@ int devm_reboot_mode_register(struct device *dev,
> if (!dr)
> return -ENOMEM;
>
> - rc = reboot_mode_register(reboot);
> + rc = reboot_mode_register(reboot, reboot->dev->of_node);
> if (rc) {
> devres_free(dr);
> return rc;
> diff --git a/include/linux/reboot-mode.h b/include/linux/reboot-mode.h
> index 4a2abb38d1d612ec0fdf05eb18c98b210f631b7f..36f071f4b82e1fc255d8dd679a18e537655c3179 100644
> --- a/include/linux/reboot-mode.h
> +++ b/include/linux/reboot-mode.h
> @@ -9,7 +9,7 @@ struct reboot_mode_driver {
> struct notifier_block reboot_notifier;
> };
>
> -int reboot_mode_register(struct reboot_mode_driver *reboot);
> +int reboot_mode_register(struct reboot_mode_driver *reboot, struct device_node *np);
> int reboot_mode_unregister(struct reboot_mode_driver *reboot);
> int devm_reboot_mode_register(struct device *dev,
> struct reboot_mode_driver *reboot);
>
> --
> 2.34.1
>
--
With best wishes
Dmitry
Powered by blists - more mailing lists