Re: [PATCH] PCI/sysfs: hide boot_display definition when VIDEO=n

From: Randy Dunlap
Date: Mon Jul 21 2025 - 17:08:35 EST


Hi Mario,

On 7/21/25 2:05 PM, Limonciello, Mario wrote:
> On 7/21/25 4:02 PM, Randy Dunlap wrote:
>> When CONFIG_VIDEO is not set, defining the 'boot_display' attribute
>> causes build errors/warnings, so hide the declaration as is done with
>> other code that uses this variable. Bracket unused code inside
>> #ifdef CONFIG_VIDEO/#endif to prevent other build warnings/errors.
>>
>> include/linux/device.h:199:33: warning: 'dev_attr_boot_display' defined but not used [-Wunused-variable]
>> 199 | struct device_attribute dev_attr_##_name = __ATTR_RO(_name)
>> drivers/pci/pci-sysfs.c:688:8: note: in expansion of macro 'DEVICE_ATTR_RO'
>> 688 | static DEVICE_ATTR_RO(boot_display);
>>
>> drivers/pci/pci-sysfs.c:683:16: warning: ‘boot_display_show’ defined but not used [-Wunused-function]
>> 683 | static ssize_t boot_display_show(struct device *dev,
>> | ^~~~~~~~~~~~~~~~~
>>
>> Fixes: c4f2dc1e5293c ("PCI: Add a new 'boot_display' attribute")
>> Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
>
> Hi Randy,
>
> Thanks for the patch. Stephen raised this last week too and it's
> brought up some other interesting topics as part of fixing it.
>
> I have two other approaches on the mailing list right now waiting for
> review.
>
> 1) Make a static sysfs file.
> https://lore.kernel.org/linux-pci/20250721023818.2410062-1-superm1@xxxxxxxxxx/T/#u
>
> 2) Move out of PCI into DRM.
> https://lore.kernel.org/linux-pci/20250721185726.1264909-1-superm1@xxxxxxxxxx/T/#me4356b3a172cbdafe83393bedce10f17a86e0da7

Yes, I found the second one just after I sent the patch.
Anyway, my patch is not relevant now.

Thanks.

--
~Randy