Re: [PATCH 1/8] wifi: ath12k: ath12k_mac_vdev_create(): use goto for error handling

[Kalle Valo <kvalo@kernel.org>]

Jeff Johnson <quic_jjohnson@quicinc.com> writes:

> On 10/23/2024 6:29 AM, Kalle Valo wrote:
>> From: Kalle Valo <quic_kvalo@quicinc.com>
>> 
>> In commit 477cabfdb776 ("wifi: ath12k: modify link arvif creation and removal
>> for MLO") I had accidentally left one personal TODO comment about using goto
>> instead of ret. Switch to use goto to be consistent with the error handling in
>> the function.
>> 
>> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
>> 
>> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
>> ---
>>  drivers/net/wireless/ath/ath12k/mac.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>> 
>> diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
>> index f5f96a8b1d61..f45f32f3b5f6 100644
>> --- a/drivers/net/wireless/ath/ath12k/mac.c
>> +++ b/drivers/net/wireless/ath/ath12k/mac.c
>> @@ -7047,8 +7047,7 @@ int ath12k_mac_vdev_create(struct ath12k *ar, struct ath12k_link_vif *arvif)
>>  		ret = ath12k_wait_for_peer_delete_done(ar, arvif->vdev_id,
>>  						       arvif->bssid);
>>  		if (ret)
>> -			/* KVALO: why not goto err? */
>> -			return ret;
>> +			goto err;
>
> why does this goto err instead of err_vdev_del?

Good point. I did this to follow the same as the next command does:

		ret = ath12k_wait_for_peer_delete_done(ar, arvif->vdev_id,
						       arvif->bssid);
		if (ret)
			goto err;

But yeah, err_vdev_del looks like more approriate.

>
>>  
>>  		ar->num_peers--;
>>  	}
>
> looking at the context for this patch I have a question about a different part
> of this function:
>
> 	param_id = WMI_VDEV_PARAM_RTS_THRESHOLD;
> 	param_value = hw->wiphy->rts_threshold;
> 	ret = ath12k_wmi_vdev_set_param_cmd(ar, arvif->vdev_id,
> 					    param_id, param_value);
> 	if (ret) {
> 		ath12k_warn(ar->ab, "failed to set rts threshold for vdev %d: %d\n",
> 			    arvif->vdev_id, ret);
>
> NOTE: no return or goto
>
> 	}
>
> 	ath12k_dp_vdev_tx_attach(ar, arvif);
> 	if (vif->type != NL80211_IFTYPE_MONITOR && ar->monitor_conf_enabled)
> 		ath12k_mac_monitor_vdev_create(ar);
>
> 	return ret;
>
> NOTE: this can return an error if the RTS threshold set fails, but fails
> without cleaning up (dp vdev still attached and monitor vdev created)
>
> Seems either we need error handling if the set param fails, or we should ret 0
> at this point

Yeah, I do not like this kind of vague error handling at all. I think we
should have either a proper error handling or a comment explaining why
we continue to the execution. An example about the comment:

ret = foo();
if (ret)
        ath12k_warn("foo failed: %d", ret);
        /* continue function because foo is optional */

I think this should all this should be cleaned up in a separate patch.

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