Re: [PATCH] drm/xe/madvise: Remove unreachable madvise_funcs NULL check

["Wang, X" <x.wang@intel.com>]

On 9/24/2026 13:44, Lin, Shuicheng wrote:
> On Thu, Sep 24, 2026 11:31 AM Xin Wang wrote:
>> On 9/14/2026 18:12, Shuicheng Lin wrote:
>>> The NULL check on madvise_funcs[attr_type] in xe_vm_madvise_ioctl() is
>>> unreachable. madvise_args_are_sane() already validates args->type via
>>> a switch statement whose default case rejects any type not present in
>>> madvise_funcs[]. Every type that passes the sanity check has a
>>> corresponding entry in the table.
>>>
>>> Beyond being dead code, the check's error path (goto err_fini) would
>>> also skip xe_svm_notifier_unlock() if it were somehow reached with
>>> has_svm_userptr_vmas set, since err_fini only tears down the drm_exec.
>>> Removing the check eliminates both the redundancy and the latent
>>> unwind hazard.
>>>
>>> No functional change.
>>>
>>> Assisted-by: LLM
>> The code change looks good to me. One small commit-message nit:
>> Documentation/process/coding-assistants.rst specifies the format
>> "Assisted-by: AGENT_NAME:MODEL_VERSION". Could you replace
>> "Assisted-by: LLM" with the tool and model version used? If it was the same
>> as v1, you could restore its Assisted-by tag.
> Thanks for the review.
> LLM is the latest suggestion of the doc as below.
> "
> -  Assisted-by: AGENT_NAME:MODEL_VERSION [TOOL1] [TOOL2]
> +  Assisted-by: LLM [TOOL1] [TOOL2]
> "
>
> Shuicheng
You're right. I checked an older version of the documentation and
missed the update to the Assisted-by format. "Assisted-by: LLM" is
correct here. Sorry for the noise; please disregard my comment about
that tag.

My Reviewed-by stands.

Thanks,
Xin

>> Reviewed-by: Xin Wang <x.wang@intel.com>
>>> Signed-off-by: Shuicheng Lin <shuicheng.lin@intel.com>
>>> ---
>>> Cc: Arvind Yadav <arvind.yadav@intel.com>
>>> Cc: Matthew Brost <matthew.brost@intel.com>
>>> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
>>> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
>>> ---
>>>    drivers/gpu/drm/xe/xe_vm_madvise.c | 6 ------
>>>    1 file changed, 6 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/xe/xe_vm_madvise.c
>>> b/drivers/gpu/drm/xe/xe_vm_madvise.c
>>> index 0474768a38aa..5c7aefc641ee 100644
>>> --- a/drivers/gpu/drm/xe/xe_vm_madvise.c
>>> +++ b/drivers/gpu/drm/xe/xe_vm_madvise.c
>>> @@ -713,12 +713,6 @@ int xe_vm_madvise_ioctl(struct drm_device *dev,
>>> void *data, struct drm_file *fil
>>>
>>>    	attr_type = array_index_nospec(args->type,
>>> ARRAY_SIZE(madvise_funcs));
>>>
>>> -	/* Ensure the madvise function exists for this type */
>>> -	if (!madvise_funcs[attr_type]) {
>>> -		err = -EINVAL;
>>> -		goto err_fini;
>>> -	}
>>> -
>>>    	madvise_funcs[attr_type](xe, vm, madvise_range.vmas,
>> madvise_range.num_vmas, args,
>>>    				 &details);
>>>