[PATCH v2] drm/dp_mst: Fix W=1 warnings

Benjamin GAIGNARD benjamin.gaignard at st.com
Thu Nov 28 13:26:37 UTC 2019


On 11/28/19 12:21 PM, Jani Nikula wrote:
> On Thu, 28 Nov 2019, Benjamin Gaignard <benjamin.gaignard at st.com> wrote:
>> Fix the warnings that show up with W=1.
>> They are all about unused but set variables.
>> If functions returns are not used anymore make them void.
>>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard at st.com>
>> CC: Jani Nikula <jani.nikula at linux.intel.com>
>> ---
>> changes in version 2:
>> - fix indentations
>> - when possible change functions prototype to void
>>
>> Note: this patch may conflict with c485e2c97dae ("drm/dp_mst: Refactor pdt
>> setup/teardown, add more locking") when it will hit drm-misc-next
> Well, why create an unnecessary conflict when the referenced commit also
> fixes the same warnings as a side-effect?

Because this commit is not merged (yet ?) in drm-misc-next which where I 
start.

Benjamin

> BR,
> Jani.
>
>
>>   drivers/gpu/drm/drm_dp_mst_topology.c | 83 +++++++++++++----------------------
>>   1 file changed, 31 insertions(+), 52 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
>> index b854a422a523..ff2d81db0778 100644
>> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
>> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
>> @@ -672,7 +672,6 @@ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
>>   				      u8 *replybuf, u8 replybuflen, bool hdr)
>>   {
>>   	int ret;
>> -	u8 crc4;
>>   
>>   	if (hdr) {
>>   		u8 hdrlen;
>> @@ -714,8 +713,6 @@ static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
>>   	}
>>   
>>   	if (msg->curchunk_idx >= msg->curchunk_len) {
>> -		/* do CRC */
>> -		crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
>>   		/* copy chunk into bigger msg */
>>   		memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
>>   		msg->curlen += msg->curchunk_len - 1;
>> @@ -1012,7 +1009,7 @@ static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
>>   	}
>>   }
>>   
>> -static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
>> +static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
>>   {
>>   	struct drm_dp_sideband_msg_req_body req;
>>   
>> @@ -1022,17 +1019,14 @@ static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32
>>   	req.u.dpcd_write.num_bytes = num_bytes;
>>   	req.u.dpcd_write.bytes = bytes;
>>   	drm_dp_encode_sideband_req(&req, msg);
>> -
>> -	return 0;
>>   }
>>   
>> -static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
>> +static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
>>   {
>>   	struct drm_dp_sideband_msg_req_body req;
>>   
>>   	req.req_type = DP_LINK_ADDRESS;
>>   	drm_dp_encode_sideband_req(&req, msg);
>> -	return 0;
>>   }
>>   
>>   static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
>> @@ -1046,7 +1040,7 @@ static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int por
>>   	return 0;
>>   }
>>   
>> -static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
>> +static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
>>   				  u8 vcpi, uint16_t pbn,
>>   				  u8 number_sdp_streams,
>>   				  u8 *sdp_stream_sink)
>> @@ -1062,10 +1056,9 @@ static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_n
>>   		   number_sdp_streams);
>>   	drm_dp_encode_sideband_req(&req, msg);
>>   	msg->path_msg = true;
>> -	return 0;
>>   }
>>   
>> -static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
>> +static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
>>   				  int port_num, bool power_up)
>>   {
>>   	struct drm_dp_sideband_msg_req_body req;
>> @@ -1078,7 +1071,6 @@ static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
>>   	req.u.port_num.port_number = port_num;
>>   	drm_dp_encode_sideband_req(&req, msg);
>>   	msg->path_msg = true;
>> -	return 0;
>>   }
>>   
>>   static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
>> @@ -1744,14 +1736,13 @@ static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
>>    */
>>   static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
>>   {
>> -	int ret;
>>   	u8 rad[6], lct;
>>   	bool send_link = false;
>>   	switch (port->pdt) {
>>   	case DP_PEER_DEVICE_DP_LEGACY_CONV:
>>   	case DP_PEER_DEVICE_SST_SINK:
>>   		/* add i2c over sideband */
>> -		ret = drm_dp_mst_register_i2c_bus(&port->aux);
>> +		drm_dp_mst_register_i2c_bus(&port->aux);
>>   		break;
>>   	case DP_PEER_DEVICE_MST_BRANCHING:
>>   		lct = drm_dp_calculate_rad(port, rad);
>> @@ -1821,25 +1812,20 @@ ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
>>   
>>   static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
>>   {
>> -	int ret;
>> -
>>   	memcpy(mstb->guid, guid, 16);
>>   
>>   	if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
>>   		if (mstb->port_parent) {
>> -			ret = drm_dp_send_dpcd_write(
>> -					mstb->mgr,
>> -					mstb->port_parent,
>> -					DP_GUID,
>> -					16,
>> -					mstb->guid);
>> +			drm_dp_send_dpcd_write(mstb->mgr,
>> +					       mstb->port_parent,
>> +					       DP_GUID,
>> +					       16,
>> +					       mstb->guid);
>>   		} else {
>> -
>> -			ret = drm_dp_dpcd_write(
>> -					mstb->mgr->aux,
>> -					DP_GUID,
>> -					mstb->guid,
>> -					16);
>> +			drm_dp_dpcd_write(mstb->mgr->aux,
>> +					  DP_GUID,
>> +					  mstb->guid,
>> +					  16);
>>   		}
>>   	}
>>   }
>> @@ -2195,7 +2181,7 @@ static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
>>   	return false;
>>   }
>>   
>> -static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
>> +static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
>>   {
>>   	struct drm_dp_sideband_msg_req_body req;
>>   
>> @@ -2204,8 +2190,6 @@ static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32
>>   	req.u.dpcd_read.dpcd_address = offset;
>>   	req.u.dpcd_read.num_bytes = num_bytes;
>>   	drm_dp_encode_sideband_req(&req, msg);
>> -
>> -	return 0;
>>   }
>>   
>>   static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
>> @@ -2427,14 +2411,14 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
>>   {
>>   	struct drm_dp_sideband_msg_tx *txmsg;
>>   	struct drm_dp_link_address_ack_reply *reply;
>> -	int i, len, ret;
>> +	int i, ret;
>>   
>>   	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
>>   	if (!txmsg)
>>   		return;
>>   
>>   	txmsg->dst = mstb;
>> -	len = build_link_address(txmsg);
>> +	build_link_address(txmsg);
>>   
>>   	mstb->link_address_sent = true;
>>   	drm_dp_queue_down_tx(mgr, txmsg);
>> @@ -2476,7 +2460,6 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
>>   {
>>   	struct drm_dp_enum_path_resources_ack_reply *path_res;
>>   	struct drm_dp_sideband_msg_tx *txmsg;
>> -	int len;
>>   	int ret;
>>   
>>   	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
>> @@ -2484,7 +2467,7 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
>>   		return -ENOMEM;
>>   
>>   	txmsg->dst = mstb;
>> -	len = build_enum_path_resources(txmsg, port->port_num);
>> +	build_enum_path_resources(txmsg, port->port_num);
>>   
>>   	drm_dp_queue_down_tx(mgr, txmsg);
>>   
>> @@ -2567,7 +2550,7 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
>>   {
>>   	struct drm_dp_sideband_msg_tx *txmsg;
>>   	struct drm_dp_mst_branch *mstb;
>> -	int len, ret, port_num;
>> +	int ret, port_num;
>>   	u8 sinks[DRM_DP_MAX_SDP_STREAMS];
>>   	int i;
>>   
>> @@ -2592,9 +2575,9 @@ static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
>>   		sinks[i] = i;
>>   
>>   	txmsg->dst = mstb;
>> -	len = build_allocate_payload(txmsg, port_num,
>> -				     id,
>> -				     pbn, port->num_sdp_streams, sinks);
>> +	build_allocate_payload(txmsg, port_num,
>> +			       id,
>> +			       pbn, port->num_sdp_streams, sinks);
>>   
>>   	drm_dp_queue_down_tx(mgr, txmsg);
>>   
>> @@ -2623,7 +2606,7 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
>>   				 struct drm_dp_mst_port *port, bool power_up)
>>   {
>>   	struct drm_dp_sideband_msg_tx *txmsg;
>> -	int len, ret;
>> +	int ret;
>>   
>>   	port = drm_dp_mst_topology_get_port_validated(mgr, port);
>>   	if (!port)
>> @@ -2636,7 +2619,7 @@ int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
>>   	}
>>   
>>   	txmsg->dst = port->parent;
>> -	len = build_power_updown_phy(txmsg, port->port_num, power_up);
>> +	build_power_updown_phy(txmsg, port->port_num, power_up);
>>   	drm_dp_queue_down_tx(mgr, txmsg);
>>   
>>   	ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
>> @@ -2856,7 +2839,6 @@ static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
>>   				 struct drm_dp_mst_port *port,
>>   				 int offset, int size, u8 *bytes)
>>   {
>> -	int len;
>>   	int ret = 0;
>>   	struct drm_dp_sideband_msg_tx *txmsg;
>>   	struct drm_dp_mst_branch *mstb;
>> @@ -2871,7 +2853,7 @@ static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
>>   		goto fail_put;
>>   	}
>>   
>> -	len = build_dpcd_read(txmsg, port->port_num, offset, size);
>> +	build_dpcd_read(txmsg, port->port_num, offset, size);
>>   	txmsg->dst = port->parent;
>>   
>>   	drm_dp_queue_down_tx(mgr, txmsg);
>> @@ -2909,7 +2891,6 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
>>   				  struct drm_dp_mst_port *port,
>>   				  int offset, int size, u8 *bytes)
>>   {
>> -	int len;
>>   	int ret;
>>   	struct drm_dp_sideband_msg_tx *txmsg;
>>   	struct drm_dp_mst_branch *mstb;
>> @@ -2924,7 +2905,7 @@ static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
>>   		goto fail_put;
>>   	}
>>   
>> -	len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
>> +	build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
>>   	txmsg->dst = mstb;
>>   
>>   	drm_dp_queue_down_tx(mgr, txmsg);
>> @@ -3147,7 +3128,7 @@ static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
>>   {
>>   	int len;
>>   	u8 replyblock[32];
>> -	int replylen, origlen, curreply;
>> +	int replylen, curreply;
>>   	int ret;
>>   	struct drm_dp_sideband_msg_rx *msg;
>>   	int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
>> @@ -3167,7 +3148,6 @@ static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
>>   	}
>>   	replylen = msg->curchunk_len + msg->curchunk_hdrlen;
>>   
>> -	origlen = replylen;
>>   	replylen -= len;
>>   	curreply = len;
>>   	while (replylen > 0) {
>> @@ -3959,17 +3939,16 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
>>   	mutex_lock(&mgr->lock);
>>   	if (mgr->mst_primary) {
>>   		u8 buf[DP_PAYLOAD_TABLE_SIZE];
>> -		int ret;
>>   
>> -		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
>> +		drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
>>   		seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
>> -		ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
>> +		drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
>>   		seq_printf(m, "faux/mst: %*ph\n", 2, buf);
>> -		ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
>> +		drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
>>   		seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
>>   
>>   		/* dump the standard OUI branch header */
>> -		ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
>> +		drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
>>   		seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
>>   		for (i = 0x3; i < 0x8 && buf[i]; i++)
>>   			seq_printf(m, "%c", buf[i]);


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