[PATCH] wifi: iwlwifi: cfg: Limit cb_size to valid range

[PATCH] wifi: iwlwifi: cfg: Limit cb_size to valid range

[Pei Xiao]

on arm64 defconfig build failed with gcc-8:

drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c:208:3:
include/linux/bitfield.h:195:3: error: call to '__field_overflow'
declared with attribute error: value doesn't fit into mask
   __field_overflow();     \
   ^~~~~~~~~~~~~~~~~~
include/linux/bitfield.h:215:2: note: in expansion of macro '____MAKE_OP'
  ____MAKE_OP(u##size,u##size,,)
  ^~~~~~~~~~~
include/linux/bitfield.h:218:1: note: in expansion of macro '__MAKE_OP'
 __MAKE_OP(32)

Limit cb_size to valid range to fix it.

Signed-off-by: Pei Xiao <xiaopei01@kylinos.cn>
---
 drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c b/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c
index cb36baac14da..8437763dcf5a 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c
@@ -166,7 +166,7 @@ int iwl_pcie_ctxt_info_init(struct iwl_trans *trans,
 	struct iwl_trans_pcie *trans_pcie = IWL_TRANS_GET_PCIE_TRANS(trans);
 	struct iwl_context_info *ctxt_info;
 	struct iwl_context_info_rbd_cfg *rx_cfg;
-	u32 control_flags = 0, rb_size;
+	u32 control_flags = 0, rb_size, cb_size;
 	dma_addr_t phys;
 	int ret;
 
@@ -202,11 +202,14 @@ int iwl_pcie_ctxt_info_init(struct iwl_trans *trans,
 		rb_size = IWL_CTXT_INFO_RB_SIZE_4K;
 	}
 
-	WARN_ON(RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)) > 12);
+	cb_size = RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans));
+	if (unlikely(cb_size > 12)) {
+		WARN_ON(1);
+		cb_size = 12;
+	}
+
 	control_flags = IWL_CTXT_INFO_TFD_FORMAT_LONG;
-	control_flags |=
-		u32_encode_bits(RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)),
-				IWL_CTXT_INFO_RB_CB_SIZE);
+	control_flags |= u32_encode_bits(cb_size, IWL_CTXT_INFO_RB_CB_SIZE);
 	control_flags |= u32_encode_bits(rb_size, IWL_CTXT_INFO_RB_SIZE);
 	ctxt_info->control.control_flags = cpu_to_le32(control_flags);
 
-- 
2.25.1

Re: [PATCH] wifi: iwlwifi: cfg: Limit cb_size to valid range

[Johannes Berg]

On Fri, 2025-05-23 at 14:04 +0800, Pei Xiao wrote:
> 
>  
> -	WARN_ON(RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)) > 12);
> +	cb_size = RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans));
> +	if (unlikely(cb_size > 12)) {
> +		WARN_ON(1);
> 

What's wrong with "if (WARN_ON(...))"?!?

Not that I think it even really needs to be there but I guess working
around a compiler warning could be worth it.

johannes

Re: [PATCH] wifi: iwlwifi: cfg: Limit cb_size to valid range

[Pei Xiao]

在 2025/5/23 15:59, Johannes Berg 写道:
> On Fri, 2025-05-23 at 14:04 +0800, Pei Xiao wrote:
>>  
>> -	WARN_ON(RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)) > 12);
>> +	cb_size = RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans));
>> +	if (unlikely(cb_size > 12)) {
>> +		WARN_ON(1);
>>
> What's wrong with "if (WARN_ON(...))"?!?
ok,thanks!
> Not that I think it even really needs to be there but I guess working
> around a compiler warning could be worth it.
yes!
> johannes

Pei.

Thanks !

Re: [PATCH] wifi: iwlwifi: cfg: Limit cb_size to valid range

[Pei Xiao]

在 2025/5/23 15:59, Johannes Berg 写道:
> On Fri, 2025-05-23 at 14:04 +0800, Pei Xiao wrote:
>>  
>> -	WARN_ON(RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)) > 12);
>> +	cb_size = RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans));
>> +	if (unlikely(cb_size > 12)) {
>> +		WARN_ON(1);
>>
> What's wrong with "if (WARN_ON(...))"?!?

thanks!

V2:

https://lore.kernel.org/lkml/7b373a4426070d50b5afb3269fd116c18ce3aea8.1748332709.git.xiaopei01@kylinos.cn/

> Not that I think it even really needs to be there but I guess working
> around a compiler warning could be worth it.
>
> johannes
Pei.Thanks!