On September 30, 2024 1:49:41 PM GMT+03:00, Heiner Kallweit <hkallweit1@xxxxxxxxx> wrote:
>On 22.09.2024 16:55, Dmitry Baryshkov wrote:
>> On Sun, Sep 08, 2024 at 02:08:58PM GMT, Heiner Kallweit wrote:
>>> This undocumented attribute returns a version string which hasn't been
>>> changed for ages. libdrm doesn't use it and I also found no other user.
>>> So I think we can remove it.
>>
>> This file is a part of the ABI. Commit 82d5e73f6b79 ("drm: drop obsolete
>> drm_core.h") replaced variable string with the fixed value that we
>> currently have, but at the same it clearly documented that the file is
>> being preserved for the sake of binary compatibility.
>>
>The drm version attribute is documented neither under Documentation/gpu
>nor under Documentation/ABI. So do we really have to consider it
>part of the ABI? And are you aware of any actual user of this attribute?
>
>The author of 82d5e73f6b79 wasn't sure either, and therefore didn't
>dare to drop the attribute (8 yrs ago). He didn't make any statement that
>the attribute is actually used.
A very quick search points out that the file is being used:
<https://codesearch.debian.net/search?q=drm%2Fversion>
>
>6.12-rc1 is just out, so we could drop the attribute in linux-next and
>would have several weeks before the next merge window to find out
>whether anybody complains.
No, this is not the way to treat userspace ABI.
>
>>>
>>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>>> ---
>>> drivers/gpu/drm/drm_sysfs.c | 12 ------------
>>> 1 file changed, 12 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
>>> index fb3bbb6ad..49e5faf11 100644
>>> --- a/drivers/gpu/drm/drm_sysfs.c
>>> +++ b/drivers/gpu/drm/drm_sysfs.c
>>> @@ -126,8 +126,6 @@ static const struct component_ops typec_connector_ops = {
>>> .unbind = typec_connector_unbind,
>>> };
>>>
>>> -static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
>>> -
>>> /**
>>> * drm_sysfs_init - initialize sysfs helpers
>>> *
>>> @@ -140,19 +138,10 @@ static CLASS_ATTR_STRING(version, S_IRUGO, "drm 1.1.0 20060810");
>>> */
>>> int drm_sysfs_init(void)
>>> {
>>> - int err;
>>> -
>>> drm_class = class_create("drm");
>>> if (IS_ERR(drm_class))
>>> return PTR_ERR(drm_class);
>>>
>>> - err = class_create_file(drm_class, &class_attr_version.attr);
>>> - if (err) {
>>> - class_destroy(drm_class);
>>> - drm_class = NULL;
>>> - return err;
>>> - }
>>> -
>>> drm_class->devnode = drm_devnode;
>>>
>>> drm_sysfs_acpi_register();
>>> @@ -169,7 +158,6 @@ void drm_sysfs_destroy(void)
>>> if (IS_ERR_OR_NULL(drm_class))
>>> return;
>>> drm_sysfs_acpi_unregister();
>>> - class_remove_file(drm_class, &class_attr_version.attr);
>>> class_destroy(drm_class);
>>> drm_class = NULL;
>>> }
>>> --
>>> 2.46.0
>>>
>>>
>>
>
--
With best wishes
Dmitry
