Re: [PATCH v1 01/17] hwmon: pmbus: adm1266: Change nvmem reg_read/write return type

[Joy Chakraborty]

On Thu, Jun 6, 2024 at 2:59 AM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On 6/5/24 10:59, Joy Chakraborty wrote:
> > Change nvmem read/write function definition return type to ssize_t.
> >
> > Signed-off-by: Joy Chakraborty <joychakr@xxxxxxxxxx>
> > ---
> >   drivers/hwmon/pmbus/adm1266.c | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/hwmon/pmbus/adm1266.c b/drivers/hwmon/pmbus/adm1266.c
> > index 2c4d94cc8729..7eaab5a7b04c 100644
> > --- a/drivers/hwmon/pmbus/adm1266.c
> > +++ b/drivers/hwmon/pmbus/adm1266.c
> > @@ -375,7 +375,7 @@ static int adm1266_nvmem_read_blackbox(struct adm1266_data *data, u8 *read_buff)
> >       return 0;
> >   }
> >
> > -static int adm1266_nvmem_read(void *priv, unsigned int offset, void *val, size_t bytes)
> > +static ssize_t adm1266_nvmem_read(void *priv, unsigned int offset, void *val, size_t bytes)
> >   {
> >       struct adm1266_data *data = priv;
> >       int ret;
> > @@ -395,7 +395,7 @@ static int adm1266_nvmem_read(void *priv, unsigned int offset, void *val, size_t
> >
> >       memcpy(val, data->dev_mem + offset, bytes);
> >
> > -     return 0;
> > +     return bytes;
> >   }
> >
> >   static int adm1266_config_nvmem(struct adm1266_data *data)
>
> The series doesn't explain what a driver is supposed to do if it
> only transfers part of the data but not all of it due to an error,
> or because the request exceeded the size of the media.
>
This patch series is actually a follow up on
https://lore.kernel.org/all/20240206042408.224138-1-joychakr@xxxxxxxxxx/
which has now been reverted . I shall try to collate it and send it
again with a better explanation.

> For example, this driver still returns an error code if it successfully
> transferred some data but not all of it, or if more data was requested
> than is available.
>
> I didn't check other drivers, but I would assume that many of them
> have the same or a similar problem.
>
> Guenter
>