Re: [PATCH] wifi: iwlwifi: pcie: ensure RX_QUEUE_CB_SIZE fits bitfield for gcc-8|9

[Johannes Berg]

> 
> diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c b/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c
> index cb36baac14da..1854d071aff2 100644
> --- a/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c
> +++ b/drivers/net/wireless/intel/iwlwifi/pcie/ctxt-info.c
> @@ -204,9 +204,10 @@ int iwl_pcie_ctxt_info_init(struct iwl_trans *trans,
>  
>  	WARN_ON(RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)) > 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);
> +	/* This should just be u32_encode_bits() but gcc-8 and gcc-9 fail to build */
> +	control_flags |= FIELD_PREP(IWL_CTXT_INFO_RB_CB_SIZE,
> +		RX_QUEUE_CB_SIZE(iwl_trans_get_num_rbds(trans)) &
> +		FIELD_MAX(IWL_CTXT_INFO_RB_CB_SIZE));
> 

The coding style is really confusing now though - what are arguments to
the macro and all that.

johannes