Re: [PATCH v3] drm/dp_mst: Fix W=1 warnings

On Tue, 2020-01-07 at 14:11 +0100, Benjamin Gaignard wrote:

Le ven. 20 déc. 2019 à 15:03, Benjamin Gaignard benjamin.gaignard@linaro.org a écrit :

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Le lun. 16 déc. 2019 à 09:28, Benjamin Gaignard benjamin.gaignard@linaro.org a écrit :

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Le mer. 4 déc. 2019 à 17:47, Jani Nikula jani.nikula@linux.intel.com a écrit :

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On Thu, 28 Nov 2019, Benjamin Gaignard benjamin.gaignard@st.com wrote:

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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@st.com

CC: Jani Nikula jani.nikula@linux.intel.com

changes in version 3:

• remove the hunk that may conflict with c485e2c97dae ("drm/dp_mst: Refactor pdt setup/teardown, add more locking")

changes in version 2:

• fix indentations
• when possible change functions prototype to void

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 1437bc46368b..d5cb5688b5dd 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -674,7 +674,6 @@ 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;
  

@@ -716,8 +715,6 @@ 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);

Again, someone needs to check if crc4 should be *used* instead of thrown away. Blindly throwing stuff out is not the way to go.

Hi Dave,

• Lyude who has been hacking in this code recently

gentle ping for the reviewers,

hi-actually yes, we should probably be using this instead of just dropping this. Also, I didn't write this code originally I just refactored a bunch of it - Dave Airlied is the original author, but the original version of this code was written ages ago. tbh, I think it's a safe bet to say that they probably did mean to use this but forgot to and no one noticed until now.

Thanks, Benjamin

...

...

Your are the original writer of this code, could you tell us if we can drop crc4 ao if there is something else that I have misunderstood ?

Thanks, Benjamin

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BR, Jani.

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          /* copy chunk into bigger msg */
          memcpy(&msg->msg[msg->curlen], msg->chunk, msg-

...

curchunk_len - 1);

          msg->curlen += msg->curchunk_len - 1;

@@ -1014,7 +1011,7 @@ 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;

@@ -1024,17 +1021,14 @@ 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) @@ -1048,7 +1042,7 @@ 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) @@ -1064,10 +1058,9 @@ 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; @@ -1080,7 +1073,6 @@ 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, @@ -1746,14 +1738,13 @@ 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);
  

@@ -1823,25 +1814,20 @@ 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);
          }
  }
  

} @@ -2197,7 +2183,7 @@ 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;

@@ -2206,8 +2192,6 @@ 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, @@ -2429,14 +2413,14 @@ 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);
  

@@ -2478,7 +2462,6 @@ 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);
  

@@ -2486,7 +2469,7 @@ 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);
  
  

@@ -2569,7 +2552,7 @@ 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;
  
  

@@ -2594,9 +2577,9 @@ 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);
  
  

@@ -2625,7 +2608,7 @@ 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)
  

@@ -2638,7 +2621,7 @@ 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);
  

@@ -2858,7 +2841,6 @@ 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;
  

@@ -2873,7 +2855,7 @@ 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);
  

@@ -2911,7 +2893,6 @@ 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;
  

@@ -2926,7 +2907,7 @@ 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);
  

@@ -3149,7 +3130,7 @@ 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; @@ -3169,7 +3150,6 @@ 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) {
  

@@ -3961,17 +3941,16 @@ 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]);

-- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel