wt., 10 mar 2020 o 21:59 Michael Auchter <michael.auchter@xxxxxx> napisał(a):
>
> The at24 driver attempts to read a byte from the device to validate that
> it's actually present, and if not, disables the vcc regulator and
> returns -ENODEV. However, between the read and the error handling path,
> pm_runtime_idle() is called and invokes the driver's suspend callback,
> which also disables the vcc regulator. This leads to an underflow of the
> regulator enable count if the EEPROM is not present.
>
> Move the pm_runtime_suspend() call to be after the error handling path
> to resolve this.
>
> Signed-off-by: Michael Auchter <michael.auchter@xxxxxx>
> ---
> drivers/misc/eeprom/at24.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c
> index 031eb64549af..282c9ef68ed2 100644
> --- a/drivers/misc/eeprom/at24.c
> +++ b/drivers/misc/eeprom/at24.c
> @@ -712,13 +712,14 @@ static int at24_probe(struct i2c_client *client)
> * chip is functional.
> */
> err = at24_read(at24, 0, &test_byte, 1);
> - pm_runtime_idle(dev);
> if (err) {
> pm_runtime_disable(dev);
> regulator_disable(at24->vcc_reg);
> return -ENODEV;
> }
>
> + pm_runtime_idle(dev);
> +
> if (writable)
> dev_info(dev, "%u byte %s EEPROM, writable, %u bytes/write\n",
> byte_len, client->name, at24->write_max);
> --
> 2.24.1
>
Patch applied for fixes.
Bartosz
