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Message-ID: <ccb50ec6-a0e9-e700-bd1e-220909fcc788@linaro.org>
Date:   Fri, 9 Sep 2022 10:08:02 +0100
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Subject: Re: [PATCH v2 13/20] nvmem: core: drop priv pointer in post process
 callback
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To:     Michael Walle <michael@walle.cc>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Shawn Guo <shawnguo@kernel.org>, Li Yang <leoyang.li@nxp.com>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>,
        Frank Rowand <frowand.list@gmail.com>,
        linux-mtd@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Ahmad Fatoum <a.fatoum@pengutronix.de>,
        Philipp Zabel <p.zabel@pengutronix.de>
References: <20220901221857.2600340-1-michael@walle.cc>
 <20220901221857.2600340-14-michael@walle.cc>
 <373b10aa-f5c8-28b3-88b0-f87a1a40b000@linaro.org>
 <42bc3f6796cc75baafc15c6d2c71ec92@walle.cc>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
In-Reply-To: <42bc3f6796cc75baafc15c6d2c71ec92@walle.cc>
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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,