Re: [PATCH v2 2/4] staging: fbtft: Make FB_DEVICE dependency optional
From: Andy Shevchenko <hidden>
Date: 2025-12-27 14:20:03
Also in:
dri-devel, linux-omap, linux-staging, lkml
On Fri, Dec 19, 2025 at 7:43 AM Chintan Patel [off-list ref] 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@suse.de> Suggested-by: Helge Deller <deller@gmx.de> Signed-off-by: Chintan Patel <redacted> ---
...a comment block here. It's not so important to be in the Git history since we have a lore.kernel.org archive.
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. -- With Best Regards, Andy Shevchenko