Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Sender: Guenter Roeck <groeck7@gmail.com>
Message-ID: <fc2989ce-82aa-aa70-cb11-c2cc2fefefcd@roeck-us.net>
Date:   Fri, 28 Apr 2023 12:33:23 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.0
Subject: Re: [PATCH] hwmon: (oxp-sensors) Add AYANEO 2 and Geek models
Content-Language: en-US
To:     Joaquin Aramendia <samsagax@gmail.com>
Cc:     derekjohn.clark@gmail.com, jdelvare@suse.com,
        linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20230426184420.99945-1-samsagax@gmail.com>
 <720c2b48-ca48-4ee3-9158-f453e48cb012@roeck-us.net>
 <CABgtM3i+HZJDearvBK-sBrWnfqdrsuNCDYfxASC3QVsn8rAy-Q@mail.gmail.com>
 <dfcd56d1-102d-ace6-c8b3-8f668e5f6872@roeck-us.net>
 <CABgtM3gydDb7gv-GQvu6mMku0KLAM+DSXqd4+FQDsk9jcXV3YA@mail.gmail.com>
From:   Guenter Roeck <linux@roeck-us.net>
In-Reply-To: <CABgtM3gydDb7gv-GQvu6mMku0KLAM+DSXqd4+FQDsk9jcXV3YA@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 4/28/23 12:15, Joaquin Aramendia wrote:
>>> I don't know why but the compiler would complain with the casting from
>>> enum to void*.
>>
>> Really ? I tried with both 32 bit and 64 bit targets, and the above worked
>> just fine (with W=1). I tried with gcc 10.3 as well as 11.3. What is
>> your compiler version, what exactly is the warning/error message you
>> observed, and how exactly did your code look like ?
> 
> Said something about an invalid cast of an lvalue? I can´t remember exactly

Like this, maybe ?

drivers/hwmon/oxp-sensors.c:63:26: error: lvalue required as unary ‘&’ operand

That would have been something along the line of

	.driver_data = (void *)&aok_zoe_a1,

or
	driver_data = &aok_zoe_a1,

> and couldn't reproduce it again. Will change all to your form after
> this patch gets
> merged if you like, just to keep things atomic.
> 

Please do.

Thanks,
Guenter

>>
>>> Found out that explicitly casting the enum literal before casting it
>>> to void* works and
>>> the compiler stopped complaining so I went with it.
>>>
>>
>> You are not casting the enum literal, but a pointer to it.
> 
> Yes. I'm taking an enum literal and taking its pointer to cast it to a void*.
> A little cumbersome, but maybe it can be avoided by using your proposed
> form directly and after making sure it works.
>