Message-ID: <cdcdf549-2031-e689-f98e-0a201357a5ae@linaro.org>
Date:   Fri, 10 Mar 2023 10:49:03 +0000
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Subject: Re: [PATCH v2 11/21] nvmem: core: handle the absence of expected
 layouts
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To:     Miquel Raynal <miquel.raynal@bootlin.com>
Cc:     linux-kernel@vger.kernel.org,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Michael Walle <michael@walle.cc>,
        =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= <rafal@milecki.pl>,
        Robert Marko <robert.marko@sartura.hr>,
        Luka Perkov <luka.perkov@sartura.hr>,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Rob Herring <robh+dt@kernel.org>,
        Frank Rowand <frowand.list@gmail.com>,
        devicetree@vger.kernel.org
References: <20230307165359.225361-1-miquel.raynal@bootlin.com>
 <20230307165359.225361-12-miquel.raynal@bootlin.com>
 <c37d2d5d-4a25-27de-3f80-033984232ed9@linaro.org>
 <20230310114510.0867e0bd@xps-13>
From:   Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
In-Reply-To: <20230310114510.0867e0bd@xps-13>
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On 10/03/2023 10:45, Miquel Raynal wrote:
> Hi Srinivas,
> 
> srinivas.kandagatla@linaro.org wrote on Fri, 10 Mar 2023 10:30:14 +0000:
> 
>> On 07/03/2023 16:53, Miquel Raynal wrote:
>>> Make nvmem_layout_get() return -EPROBE_DEFER while the expected layout
>>> is not available. This condition cannot be triggered today as nvmem
>>> layout drivers are initialed as part of an early init call, but soon
>>> these drivers will be converted into modules and be initialized with a
>>> standard priority, so the unavailability of the drivers might become a
>>> reality that must be taken care of.
>>>
>>> Let's anticipate this by telling the caller the layout might not yet be
>>> available. A probe deferral is requested in this case.
>>>
>>> Please note this does not affect any nvmem device not using layouts,
>>> because an early check against the "nvmem-layout" container presence
>>> will return NULL in this case.
>>>
>>> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
>>> Tested-by: Michael Walle <michael@walle.cc>
>>> ---
>>>    drivers/nvmem/core.c | 10 +++++++++-
>>>    1 file changed, 9 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
>>> index b9be1faeb7be..51fd792b8d70 100644
>>> --- a/drivers/nvmem/core.c
>>> +++ b/drivers/nvmem/core.c
>>> @@ -755,7 +755,7 @@ EXPORT_SYMBOL_GPL(nvmem_layout_unregister);
>>>    static struct nvmem_layout *nvmem_layout_get(struct nvmem_device *nvmem)
>>>    {
>>
>> Any reason why this is not part of 10/21?
> 
> Yes, I would like to credit everybody for his work, so Michael for the
> base implementation and myself for the module sitaution handling,
> arguing this is two different features. May we keep these separated?

Thanks for clarifying this, that should be fine.

--srini