Re: [PATCH v2 13/20] nvmem: core: drop priv pointer in post process callback

Srinivas Kandagatla
2022-09-09T09:08:19Z

On 09/09/2022 09:58, Michael Walle wrote:
> Am 2022-09-09 10:52, schrieb Srinivas Kandagatla:
>> On 01/09/2022 23:18, Michael Walle wrote:
>>> It doesn't make any more sense to have a opaque pointer set up by the
>>> nvmem device. Usually, the layout isn't associated with a particular
>>> nvmem device.
>>>
>> This is really not a good idea to remove the context pointer, as this
>> is the only way for callback to get context which it can make use of.
>
> In which case? As I mentioned it's the priv to the nvmem driver and all
> the "normal" callbacks can do very little with it. If there will be a
> future need, then there should be a proper opaque pointer associated
> with the layout and not the nvmem driver.

Yes, the opaque object here is the layout priv which I agree with, but
removing the context totally from the callback is not a good idea.

We should have some context to callbacks to be able to allow them to
deal with some private info.

--srini

>
> -michael
>
>> I would prefer this to be left as it is.
>>
>> --srini
>>
>>> Signed-off-by: Michael Walle <michael@walle.cc>
>>> ---
>>> changes since v1:
>>>   - new patch
>>>
>>>   drivers/nvmem/core.c           | 4 ++--
>>>   drivers/nvmem/imx-ocotp.c      | 4 ++--
>>>   include/linux/nvmem-provider.h | 5 +++--
>>>   3 files changed, 7 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
>>> index d31d3f0ab517..6910796937f9 100644
>>> --- a/drivers/nvmem/core.c
>>> +++ b/drivers/nvmem/core.c
>>> @@ -1523,8 +1523,8 @@ static int __nvmem_cell_read(struct
>>> nvmem_device *nvmem,
>>>           nvmem_shift_read_buffer_in_place(cell, buf);
>>>         if (cell->read_post_process) {
>>> -        rc = cell->read_post_process(nvmem->priv, id, index,
>>> -                         cell->offset, buf, cell->bytes);
>>> +        rc = cell->read_post_process(id, index, cell->offset, buf,
>>> +                         cell->bytes);
>>>           if (rc)
>>>               return rc;
>>>       }
>>> diff --git a/drivers/nvmem/imx-ocotp.c b/drivers/nvmem/imx-ocotp.c
>>> index ac0edb6398f1..5e869d4a81c5 100644
>>> --- a/drivers/nvmem/imx-ocotp.c
>>> +++ b/drivers/nvmem/imx-ocotp.c
>>> @@ -222,8 +222,8 @@ static int imx_ocotp_read(void *context, unsigned
>>> int offset,
>>>       return ret;
>>>   }
>>>   -static int imx_ocotp_cell_pp(void *context, const char *id, int
>>> index,
>>> -                 unsigned int offset, void *data, size_t bytes)
>>> +static int imx_ocotp_cell_pp(const char *id, int index, unsigned int
>>> offset,
>>> +                 void *data, size_t bytes)
>>>   {
>>>       u8 *buf = data;
>>>       int i;
>>> diff --git a/include/linux/nvmem-provider.h
>>> b/include/linux/nvmem-provider.h
>>> index 9d22dc5a3fa5..46067a6a0395 100644
>>> --- a/include/linux/nvmem-provider.h
>>> +++ b/include/linux/nvmem-provider.h
>>> @@ -19,8 +19,9 @@ typedef int (*nvmem_reg_read_t)(void *priv,
>>> unsigned int offset,
>>>   typedef int (*nvmem_reg_write_t)(void *priv, unsigned int offset,
>>>                    void *val, size_t bytes);
>>>   /* used for vendor specific post processing of cell data */
>>> -typedef int (*nvmem_cell_post_process_t)(void *priv, const char *id,
>>> int index,
>>> -                     unsigned int offset, void *buf, size_t bytes);
>>> +typedef int (*nvmem_cell_post_process_t)(const char *id, int index,
>>> +                     unsigned int offset, void *buf,
>>> +                     size_t bytes);
>>>     enum nvmem_type {
>>>       NVMEM_TYPE_UNKNOWN = 0,