remove defaults to None if optional
diff --git a/examples/research_projects/wav2vec2/run_asr.py b/examples/research_projects/wav2vec2/run_asr.py
index 5e62cb504eb12..410d5c2d3a622 100755
--- a/examples/research_projects/wav2vec2/run_asr.py
+++ b/examples/research_projects/wav2vec2/run_asr.py
@@ -144,7 +144,7 @@ class Orthography:
     Args:
         do_lower_case (:obj:`bool`, `optional`, defaults to :obj:`False`):
             Whether or not to accept lowercase input and lowercase the output when decoding.
-        vocab_file (:obj:`str`, `optional`, defaults to :obj:`None`):
+        vocab_file (:obj:`str`, `optional`):
             File containing the vocabulary.
         word_delimiter_token (:obj:`str`, `optional`, defaults to :obj:`"|"`):
             The token used for delimiting words; it needs to be in the vocabulary.
@@ -152,7 +152,7 @@ class Orthography:
             Table to use with `str.translate()` when preprocessing text (e.g., "-" -> " ").
         words_to_remove (:obj:`Set[str]`, `optional`, defaults to :obj:`set()`):
             Words to remove when preprocessing text (e.g., "sil").
-        untransliterator (:obj:`Callable[[str], str]`, `optional`, defaults to :obj:`None`):
+        untransliterator (:obj:`Callable[[str], str]`, `optional`):
             Function that untransliterates text back into native writing system.
     """
 
diff --git a/src/transformers/debug_utils.py b/src/transformers/debug_utils.py
index 45384a80134ba..537f897b49f84 100644
--- a/src/transformers/debug_utils.py
+++ b/src/transformers/debug_utils.py
@@ -118,7 +118,7 @@ class DebugUnderflowOverflow:
             How many frames back to record
         trace_batch_nums(:obj:`List[int]`, `optional`, defaults to ``[]``):
             Which batch numbers to trace (turns detection off)
-        abort_after_batch_num  (:obj:`int`, `optional`, defaults to :obj:`None`):
+        abort_after_batch_num  (:obj:`int`, `optional`):
             Whether to abort after a certain batch number has finished
 
     """
diff --git a/src/transformers/modeling_tf_utils.py b/src/transformers/modeling_tf_utils.py
index 4bf12af5573cf..16af519e2345e 100644
--- a/src/transformers/modeling_tf_utils.py
+++ b/src/transformers/modeling_tf_utils.py
@@ -1128,7 +1128,7 @@ def from_pretrained(cls, pretrained_model_name_or_path, *model_args, **kwargs):
                 The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
                 git-based system for storing models and other artifacts on huggingface.co, so ``revision`` can be any
                 identifier allowed by git.
-            mirror(:obj:`str`, `optional`, defaults to :obj:`None`):
+            mirror(:obj:`str`, `optional`):
                 Mirror source to accelerate downloads in China. If you are from China and have an accessibility
                 problem, you can set this option to resolve it. Note that we do not guarantee the timeliness or safety.
                 Please refer to the mirror site for more information.
diff --git a/src/transformers/modeling_utils.py b/src/transformers/modeling_utils.py
index 4247f4c2a6dbd..ca8ae2267109d 100644
--- a/src/transformers/modeling_utils.py
+++ b/src/transformers/modeling_utils.py
@@ -975,7 +975,7 @@ def from_pretrained(cls, pretrained_model_name_or_path: Optional[Union[str, os.P
                 The specific model version to use. It can be a branch name, a tag name, or a commit id, since we use a
                 git-based system for storing models and other artifacts on huggingface.co, so ``revision`` can be any
                 identifier allowed by git.
-            mirror(:obj:`str`, `optional`, defaults to :obj:`None`):
+            mirror(:obj:`str`, `optional`):
                 Mirror source to accelerate downloads in China. If you are from China and have an accessibility
                 problem, you can set this option to resolve it. Note that we do not guarantee the timeliness or safety.
                 Please refer to the mirror site for more information.
diff --git a/src/transformers/models/albert/tokenization_albert_fast.py b/src/transformers/models/albert/tokenization_albert_fast.py
index cb817ddcc01fd..9aa18317042da 100644
--- a/src/transformers/models/albert/tokenization_albert_fast.py
+++ b/src/transformers/models/albert/tokenization_albert_fast.py
@@ -172,7 +172,7 @@ def build_inputs_with_special_tokens(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of IDs to which the special tokens will be added
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
 
         Returns:
@@ -201,7 +201,7 @@ def create_token_type_ids_from_sequences(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of ids.
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
 
         Returns:
diff --git a/src/transformers/models/big_bird/tokenization_big_bird_fast.py b/src/transformers/models/big_bird/tokenization_big_bird_fast.py
index cbe2b74133165..e5b1e5bab0e28 100644
--- a/src/transformers/models/big_bird/tokenization_big_bird_fast.py
+++ b/src/transformers/models/big_bird/tokenization_big_bird_fast.py
@@ -152,7 +152,7 @@ def build_inputs_with_special_tokens(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of IDs to which the special tokens will be added
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
 
         Returns:
@@ -174,7 +174,7 @@ def get_special_tokens_mask(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of ids.
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
             already_has_special_tokens (:obj:`bool`, `optional`, defaults to :obj:`False`):
                 Set to True if the token list is already formatted with special tokens for the model
@@ -212,7 +212,7 @@ def create_token_type_ids_from_sequences(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of ids.
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
 
         Returns:
diff --git a/src/transformers/models/ibert/quant_modules.py b/src/transformers/models/ibert/quant_modules.py
index 065a3fef6144d..d1da18686abd3 100644
--- a/src/transformers/models/ibert/quant_modules.py
+++ b/src/transformers/models/ibert/quant_modules.py
@@ -124,7 +124,7 @@ class QuantAct(nn.Module):
             Momentum for updating the activation quantization range.
         per_channel (:obj:`bool`, `optional`, defaults to :obj:`False`):
             Whether to or not use channel-wise quantization.
-        channel_len (:obj:`int`, `optional`, defaults to :obj:`None`):
+        channel_len (:obj:`int`, `optional`):
             Specify the channel length when set the `per_channel` True.
         quant_mode (:obj:`bool`, `optional`, defaults to :obj:`False`):
             Whether or not the layer is quantized.
@@ -755,9 +755,9 @@ class FixedPointMul(Function):
             Quantization bitwidth.
         z_scaling_factor (:obj:`torch.Tensor`):
             Scaling factor of the output tensor.
-        identity (:obj:`torch.Tensor`, `optional`, defaults to :obj:`None`):
+        identity (:obj:`torch.Tensor`, `optional`):
             Identity tensor, if exists.
-        identity_scaling_factor (:obj:`torch.Tensor`, `optional`, defaults to :obj:`None`):
+        identity_scaling_factor (:obj:`torch.Tensor`, `optional`):
             Scaling factor of the identity tensor `identity`, if exists.
 
     Returns:
diff --git a/src/transformers/models/mpnet/modeling_mpnet.py b/src/transformers/models/mpnet/modeling_mpnet.py
index f1327a8719762..90ba92242bc62 100644
--- a/src/transformers/models/mpnet/modeling_mpnet.py
+++ b/src/transformers/models/mpnet/modeling_mpnet.py
@@ -444,7 +444,7 @@ def forward(self, hidden_states):
             details.
 
             `What are input IDs? <../glossary.html#input-ids>`__
-        attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`, defaults to :obj:`None`):
+        attention_mask (:obj:`torch.FloatTensor` of shape :obj:`(batch_size, sequence_length)`, `optional`):
             Mask to avoid performing attention on padding token indices. Mask values selected in ``[0, 1]``:
 
             - 1 for tokens that are **not masked**,
diff --git a/src/transformers/models/mpnet/tokenization_mpnet.py b/src/transformers/models/mpnet/tokenization_mpnet.py
index 98af763ade64a..7bbefb4946430 100644
--- a/src/transformers/models/mpnet/tokenization_mpnet.py
+++ b/src/transformers/models/mpnet/tokenization_mpnet.py
@@ -235,7 +235,7 @@ def build_inputs_with_special_tokens(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of IDs to which the special tokens will be added
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
 
         Returns:
diff --git a/src/transformers/models/xlm_prophetnet/tokenization_xlm_prophetnet.py b/src/transformers/models/xlm_prophetnet/tokenization_xlm_prophetnet.py
index 9c2d90914a6d8..b2707f8dcb2a7 100644
--- a/src/transformers/models/xlm_prophetnet/tokenization_xlm_prophetnet.py
+++ b/src/transformers/models/xlm_prophetnet/tokenization_xlm_prophetnet.py
@@ -290,7 +290,7 @@ def build_inputs_with_special_tokens(
         Args:
             token_ids_0 (:obj:`List[int]`):
                 List of IDs to which the special tokens will be added
-            token_ids_1 (:obj:`List[int]`, `optional`, defaults to :obj:`None`):
+            token_ids_1 (:obj:`List[int]`, `optional`):
                 Optional second list of IDs for sequence pairs.
 
         Returns:
diff --git a/src/transformers/pipelines/text2text_generation.py b/src/transformers/pipelines/text2text_generation.py
index 96aaf3d19fb84..346f178bbc920 100644
--- a/src/transformers/pipelines/text2text_generation.py
+++ b/src/transformers/pipelines/text2text_generation.py
@@ -295,10 +295,10 @@ def __call__(
                 Whether or not to include the decoded texts in the outputs.
             clean_up_tokenization_spaces (:obj:`bool`, `optional`, defaults to :obj:`False`):
                 Whether or not to clean up the potential extra spaces in the text output.
-            src_lang (:obj:`str`, `optional`, defaults to :obj:`None`):
+            src_lang (:obj:`str`, `optional`):
                 The language of the input. Might be required for multilingual models. Will not have any effect for
                 single pair translation models
-            tgt_lang (:obj:`str`, `optional`, defaults to :obj:`None`):
+            tgt_lang (:obj:`str`, `optional`):
                 The language of the desired output. Might be required for multilingual models. Will not have any effect
                 for single pair translation models
             generate_kwargs:

PR to fix #11687

