linux-kernel - Re: [PATCH v5 2/7] staging: atomisp: Do not call dev

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Date:   Sun, 28 May 2017 20:26:28 +0200
From:   Hans de Goede <hdegoede@...hat.com>
To:     Alan Cox <gnomes@...rguk.ukuu.org.uk>
Cc:     Lee Jones <lee.jones@...aro.org>, Chen-Yu Tsai <wens@...e.org>,
        linux-kernel@...r.kernel.org,
        Linux Media Mailing List <linux-media@...r.kernel.org>
Subject: Re: [PATCH v5 2/7] staging: atomisp: Do not call dev_warn with a NULL
 device

Hi,

On 28-05-17 19:08, Alan Cox wrote:
> On Sun, 28 May 2017 14:30:35 +0200
> Hans de Goede <hdegoede@...hat.com> wrote:
> 
>> Do not call dev_warn with a NULL device, this silence the following 2
>> warnings:
>>
>> [   14.392194] (NULL device *): Failed to find gmin variable gmin_V2P8GPIO
>> [   14.392257] (NULL device *): Failed to find gmin variable gmin_V1P8GPIO
>>
>> We could switch to using pr_warn for dev == NULL instead, but as comments
>> in the source indicate, the check for these 2 special gmin variables with
>> a NULL device is a workaround for 2 specific evaluation boards, so
>> completely silencing the missing warning for these actually is a good
>> thing.
> 
> At which point real missing variables won't get reported so NAK. I think
> the right fix is to make the offending callers pass
> 
> 	subdev->dev

The code for the special v1p8 / v2p8 gpios is ugly as sin, it operates on
a global v2p8_gpio value rather then storing info in the gmin_subdev struct,
as such passing the subdev->dev pointer would be simply wrong. AFAICT the
v1p8 / v2p8 gpio code is the only caller passing in a NULL pointer and
as said since thisv1p8 / v2p8 gpio code is only for some special evaluation
boards, silencing the error when these variables are not present actually
is the right thing to do.

> which if my understanding of the subdevices is correct should pass the
> right valid device field from the atomisp.
> 
> Please also cc me if you are proposing patches this driver - and also
> linux-media.

Sorry about that, I messed up my git send-email foo and send this to
a wrong set of addresses (and also added v5 in the subject which should
not be there) I did send out a fresh-copy with the full 7 patch patch-set
directly after CTRL+c-ing this wrong send-email (which only got the
first 3 patches send).

Regards,

Hans