linux-kernel - Re: [PATCH v2 2/4] staging: fbtft: Make FB

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <ec86f093-8fe8-4fc8-b330-dc7ee8a01de9@gmail.com>
Date: Sat, 27 Dec 2025 19:36:03 -0800
From: Chintan Patel <chintanlike@...il.com>
To: Andy Shevchenko <andy.shevchenko@...il.com>
Cc: linux-fbdev@...r.kernel.org, linux-staging@...ts.linux.dev,
 linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org,
 dri-devel@...ts.freedesktop.org, tzimmermann@...e.de, andy@...nel.org,
 deller@....de, gregkh@...uxfoundation.org
Subject: Re: [PATCH v2 2/4] staging: fbtft: Make FB_DEVICE dependency optional

Hi Andy,

On 12/27/25 06:19, Andy Shevchenko wrote:
> On Fri, Dec 19, 2025 at 7:43 AM Chintan Patel <chintanlike@...il.com> wrote:
>>
>> fbtft provides sysfs interfaces for debugging and gamma configuration,
>> but these are not required for the core driver.
>>
>> Drop the hard dependency on CONFIG_FB_DEVICE and make sysfs support
>> optional by using dev_of_fbinfo() at runtime. When FB_DEVICE is disabled,
>> sysfs operations are skipped while the code remains buildable and
>> type-checked.
> 
>> v2:
>> - Replace CONFIG_FB_DEVICE ifdefs with runtime checks
>> - Use dev_of_fbinfo() to guard sysfs creation and removal
> 
> The place for the change log is either a cover letter, or...
> 
>> Suggested-by: Thomas Zimmermann <tzimmermann@...e.de>
>> Suggested-by: Helge Deller <deller@....de>
>> Signed-off-by: Chintan Patel <chintanlike@...il.com>
>> ---
> 
> ...a comment block here. It's not so important to be in the Git
> history since we have a lore.kernel.org archive.

Thank you for suggestion! Will move to coverletter.

>>   drivers/staging/fbtft/Kconfig       |  5 ++++-
>>   drivers/staging/fbtft/fbtft-sysfs.c | 18 ++++++++++++++----
> 
> ...
> 
>>   void fbtft_sysfs_init(struct fbtft_par *par)
>>   {
>> -       device_create_file(par->info->dev, &debug_device_attr);
>> +       struct device *dev = dev_of_fbinfo(par->info);
>> +
>> +       if (!dev)
>> +               return;
> 
> 
> The better way is to decouple the definition and the assignment in the
> cases when it's followed by a conditional (validation check). In this
> case any new code added in between doesn't affect readability and
> maintenance efforts.
> 
>         struct device *dev;
> 
>         dev = dev_of_fbinfo(par->info);
>         if (!dev)
>                 return;
> 
>> +       device_create_file(dev, &debug_device_attr);
>>          if (par->gamma.curves && par->fbtftops.set_gamma)
>> -               device_create_file(par->info->dev, &gamma_device_attrs[0]);
>> +               device_create_file(dev, &gamma_device_attrs[0]);
>>   }
> 
> Ditto for the rest.

Will do v3 and re-send. Thanks for reviews!