2020-06-01 09:21:08

by Vadim Pasternak

Subject: [PATCH platform-next v1 2/8] platform/mellanox: mlxreg-hotplug: Add environmental data to uevent

Send "udev" event with environmental data in order to allow handling
"ENV{}" variables in "udev" rules.

Signed-off-by: Vadim Pasternak <[email protected]>
---
drivers/platform/mellanox/mlxreg-hotplug.c | 27 +++++++++++++++++++++++++--
1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/mellanox/mlxreg-hotplug.c b/drivers/platform/mellanox/mlxreg-hotplug.c
index 832fcf282d45..5420d5bb0e6c 100644
--- a/drivers/platform/mellanox/mlxreg-hotplug.c
+++ b/drivers/platform/mellanox/mlxreg-hotplug.c
@@ -97,13 +97,36 @@ struct mlxreg_hotplug_priv_data {
u8 not_asserted;
};

+/* Environment variables array for udev. */
+static char *mlxreg_hotplug_udev_envp[] = { NULL, NULL };
+
+static int
+mlxreg_hotplug_udev_event_send(struct kobject *kobj,
+ struct mlxreg_core_data *data, bool action)
+{
+ char event_str[MLXREG_CORE_LABEL_MAX_SIZE + 2];
+ char label[MLXREG_CORE_LABEL_MAX_SIZE] = { 0 };
+ int i;
+
+ mlxreg_hotplug_udev_envp[0] = event_str;
+ for (i = 0; data->label[i]; i++)
+ label[i] = toupper(data->label[i]);
+
+ if (action)
+ snprintf(event_str, MLXREG_CORE_LABEL_MAX_SIZE, "%s=1", label);
+ else
+ snprintf(event_str, MLXREG_CORE_LABEL_MAX_SIZE, "%s=0", label);
+
+ return kobject_uevent_env(kobj, KOBJ_CHANGE, mlxreg_hotplug_udev_envp);
+}
+
static int mlxreg_hotplug_device_create(struct mlxreg_hotplug_priv_data *priv,
struct mlxreg_core_data *data)
{
struct mlxreg_core_hotplug_platform_data *pdata;

/* Notify user by sending hwmon uevent. */
- kobject_uevent(&priv->hwmon->kobj, KOBJ_CHANGE);
+ mlxreg_hotplug_udev_event_send(&priv->hwmon->kobj, data, true);

/*
* Return if adapter number is negative. It could be in case hotplug
@@ -141,7 +164,7 @@ mlxreg_hotplug_device_destroy(struct mlxreg_hotplug_priv_data *priv,
struct mlxreg_core_data *data)
{
/* Notify user by sending hwmon uevent. */
- kobject_uevent(&priv->hwmon->kobj, KOBJ_CHANGE);
+ mlxreg_hotplug_udev_event_send(&priv->hwmon->kobj, data, false);

if (data->hpdev.client) {
i2c_unregister_device(data->hpdev.client);
--
2.11.0

2020-07-09 16:33:02

by Andy Shevchenko

Subject: Re: [PATCH platform-next v1 2/8] platform/mellanox: mlxreg-hotplug: Add environmental data to uevent

On Mon, Jun 1, 2020 at 12:19 PM Vadim Pasternak <[email protected]> wrote:
>
> Send "udev" event with environmental data in order to allow handling
> "ENV{}" variables in "udev" rules.

...

> +static int
> +mlxreg_hotplug_udev_event_send(struct kobject *kobj,
> + struct mlxreg_core_data *data, bool action)
> +{
> + char event_str[MLXREG_CORE_LABEL_MAX_SIZE + 2];
> + char label[MLXREG_CORE_LABEL_MAX_SIZE] = { 0 };
> + int i;
> +
> + mlxreg_hotplug_udev_envp[0] = event_str;

> + for (i = 0; data->label[i]; i++)
> + label[i] = toupper(data->label[i]);

Sounds like a candidate to be in string_helpers.h

#include <ctype.h>
...
static inline void string_upper(char *dst, const char *src)
{
do {
*dst++ = toupper(*src);
} while (*src++);
}

// similar for tolower
...

There are plenty existing users that can benefit and I can imagine how
many more will come.
So, If you add the first patch in the series to bring this in, I will take it.

> + if (action)
> + snprintf(event_str, MLXREG_CORE_LABEL_MAX_SIZE, "%s=1", label);
> + else
> + snprintf(event_str, MLXREG_CORE_LABEL_MAX_SIZE, "%s=0", label);

Wouldn't be easier to have

..."%s=%d" ... !!action...

?

> +
> + return kobject_uevent_env(kobj, KOBJ_CHANGE, mlxreg_hotplug_udev_envp);
> +}

--
With Best Regards,
Andy Shevchenko