Re: [PATCH V1] accel/amdxdna: Add ioctl DRM_IOCTL_AMDXDNA_GET_ARRAY

[Lizhi Hou <lizhi.hou@amd.com>]

On 8/26/25 10:58, Mario Limonciello wrote:
> On 8/26/2025 12:55 PM, Lizhi Hou wrote:
>>
>> On 8/26/25 10:18, Mario Limonciello wrote:
>>> On 8/25/2025 11:48 PM, Lizhi Hou wrote:
>>>>
>>>> On 8/25/25 14:28, Mario Limonciello wrote:
>>>>> On 8/22/2025 12:23 PM, Lizhi Hou wrote:
>>>>>> Add interface for applications to get information array. The 
>>>>>> application
>>>>>> provides a buffer pointer along with information type, maximum 
>>>>>> number of
>>>>>> entries and maximum size of each entry. The buffer may also 
>>>>>> contain match
>>>>>> conditions based on the information type. After the ioctl 
>>>>>> completes, the
>>>>>> actual number of entries and entry size are returned.
>>>>>>
>>>>>> Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
>>>>>
>>>>> How does userspace discover whether or not the new IOCTL call is 
>>>>> supported?  Just a test call?
>>>> The kernel header version will be used to determine whether the 
>>>> application which uses new IOCTL will be compiled or not.
>>>>
>>>
>>> But it's not actually an application compile time decision, it's a 
>>> runtime decision.  IE I can compile an application with the headers 
>>> on kernel 6.18 that has this, but if I try to run it on 6.15 it's 
>>> going to barf.
>>>
>>> To some extent that comes with the territory, but I'm wondering if a 
>>> better solution going forward would be for there to be a dedicated 
>>> version command that you bump.
>>
>> For in-tree driver, I did not aware a common way for this other than 
>> checking the kernel version.
>>
>> And here is qaic patch of adding a new IOCTL.
>>
>> https://github.com/torvalds/linux/ 
>> commit/217b812364d360e1933d8485f063400e5dda7d66
>>
>>
>> I know there is major, minor, patchlevel in struct drm_driver. And I 
>> think that is not required for in-tree driver.
>>
>> Please let me know if I missed anything.
>>
>> Thanks,
>
> Right; so bump up one of those so that userspace can check it. Maybe 
> "minor"?

I meant for in-tree driver, is it good enough for userspace to just 
check kernel version?  E.g. The drm driver versions are not used by ivpu 
or qaic.

Thanks,

Lizhi