[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <e519e9f2-5e25-4ec3-afb4-42d15da941aa@gmail.com>
Date: Sun, 30 Jun 2024 00:00:26 +0200
From: Heiner Kallweit <hkallweit1@...il.com>
To: Guenter Roeck <linux@...ck-us.net>, linux-kernel@...r.kernel.org
Cc: Arnd Bergmann <arnd@...db.de>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Thomas Weißschuh <linux@...ssschuh.net>
Subject: Re: [PATCH 1/2] eeprom: ee1004: Call i2c_new_scanned_device to
instantiate thermal sensor
On 29.06.2024 19:37, Guenter Roeck wrote:
> Instantiating a device by calling i2c_new_client_device() assumes that the
> device is not already instantiated. If that is not the case, it will return
> an error and generate a misleading kernel log message.
>
> i2c i2c-0: Failed to register i2c client jc42 at 0x18 (-16)
>
> This can be reproduced by unloading the ee1004 driver and loading it again.
>
> Avoid this by calling i2c_new_scanned_device() instead, which returns
> silently if a device is already instantiated or does not exist.
>
However i2c_new_scanned_device() runs i2c_default_probe() on the device,
whilst i2c_new_client_device() doesn't access the i2c bus.
If possible I'd like to avoid this overhead.
> Fixes: 393bd1000f81 ("eeprom: ee1004: add support for temperature sensor")
> Cc: Heiner Kallweit <hkallweit1@...il.com>
> Cc: Thomas Weißschuh <linux@...ssschuh.net>
> Signed-off-by: Guenter Roeck <linux@...ck-us.net>
> ---
> drivers/misc/eeprom/ee1004.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/misc/eeprom/ee1004.c b/drivers/misc/eeprom/ee1004.c
> index 21feebc3044c..71ca66d1df82 100644
> --- a/drivers/misc/eeprom/ee1004.c
> +++ b/drivers/misc/eeprom/ee1004.c
> @@ -185,6 +185,8 @@ BIN_ATTRIBUTE_GROUPS(ee1004);
> static void ee1004_probe_temp_sensor(struct i2c_client *client)
> {
> struct i2c_board_info info = { .type = "jc42" };
> + unsigned short addr = 0x18 | (client->addr & 7);
> + unsigned short addr_list[] = { addr, I2C_CLIENT_END };
> u8 byte14;
> int ret;
>
> @@ -193,9 +195,7 @@ static void ee1004_probe_temp_sensor(struct i2c_client *client)
> if (ret != 1 || !(byte14 & BIT(7)))
> return;
>
> - info.addr = 0x18 | (client->addr & 7);
> -
> - i2c_new_client_device(client->adapter, &info);
> + i2c_new_scanned_device(client->adapter, &info, addr_list, NULL);
> }
>
> static void ee1004_cleanup(int idx, struct ee1004_bus_data *bd)
Powered by blists - more mailing lists