drivers/gpu/drm/display/drm_dp_tunnel.c:1270:26-27: WARNING opportunity for min() (fwd)
From: Julia Lawall
Date: Fri Apr 19 2024 - 03:13:59 EST
Hello,
You can ignore the warning about min. But it could be nice to drop the
unneeded semicolon on line 1128.
julia
---------- Forwarded message ----------
Date: Fri, 19 Apr 2024 07:37:39 +0800
From: kernel test robot <lkp@xxxxxxxxx>
To: oe-kbuild@xxxxxxxxxxxxxxx
Cc: lkp@xxxxxxxxx, Julia Lawall <julia.lawall@xxxxxxxx>
Subject: drivers/gpu/drm/display/drm_dp_tunnel.c:1270:26-27: WARNING opportunity
for min()
BCC: lkp@xxxxxxxxx
CC: oe-kbuild-all@xxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
TO: Imre Deak <imre.deak@xxxxxxxxx>
CC: "Ville Syrjälä" <ville.syrjala@xxxxxxxxxxxxxxx>
CC: Uma Shankar <uma.shankar@xxxxxxxxx>
tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 2668e3ae2ef36d5e7c52f818ad7d90822c037de4
commit: 91888b5b1ad2fda3f4c6b8de5dd42dbe8b90ac2c drm/i915/dp: Add support for DP tunnel BW allocation
date: 7 weeks ago
:::::: branch date: 4 hours ago
:::::: commit date: 7 weeks ago
config: i386-randconfig-052-20240419 (https://download.01.org/0day-ci/archive/20240419/202404190730.awqNW3rH-lkp@xxxxxxxxx/config)
compiler: clang version 17.0.6 (https://github.com/llvm/llvm-project 6009708b4367171ccdbf4b5905cb6a803753fe18)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Julia Lawall <julia.lawall@xxxxxxxx>
| Closes: https://lore.kernel.org/r/202404190730.awqNW3rH-lkp@xxxxxxxxx/
cocci warnings: (new ones prefixed by >>)
>> drivers/gpu/drm/display/drm_dp_tunnel.c:1270:26-27: WARNING opportunity for min()
--
>> drivers/gpu/drm/display/drm_dp_tunnel.c:1128:2-3: Unneeded semicolon
vim +1270 drivers/gpu/drm/display/drm_dp_tunnel.c
295654f7e554a9f Imre Deak 2024-02-26 1071
295654f7e554a9f Imre Deak 2024-02-26 1072 static int allocate_tunnel_bw(struct drm_dp_tunnel *tunnel, int bw)
295654f7e554a9f Imre Deak 2024-02-26 1073 {
295654f7e554a9f Imre Deak 2024-02-26 1074 struct drm_dp_tunnel_mgr *mgr = tunnel->group->mgr;
295654f7e554a9f Imre Deak 2024-02-26 1075 int request_bw = DIV_ROUND_UP(bw, tunnel->bw_granularity);
295654f7e554a9f Imre Deak 2024-02-26 1076 DEFINE_WAIT_FUNC(wait, woken_wake_function);
295654f7e554a9f Imre Deak 2024-02-26 1077 long timeout;
295654f7e554a9f Imre Deak 2024-02-26 1078 int err;
295654f7e554a9f Imre Deak 2024-02-26 1079
295654f7e554a9f Imre Deak 2024-02-26 1080 if (bw < 0) {
295654f7e554a9f Imre Deak 2024-02-26 1081 err = -EINVAL;
295654f7e554a9f Imre Deak 2024-02-26 1082 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1083 }
295654f7e554a9f Imre Deak 2024-02-26 1084
295654f7e554a9f Imre Deak 2024-02-26 1085 if (request_bw * tunnel->bw_granularity == tunnel->allocated_bw)
295654f7e554a9f Imre Deak 2024-02-26 1086 return 0;
295654f7e554a9f Imre Deak 2024-02-26 1087
295654f7e554a9f Imre Deak 2024-02-26 1088 /* Atomic check should prevent the following. */
295654f7e554a9f Imre Deak 2024-02-26 1089 if (drm_WARN_ON(mgr->dev, request_bw > MAX_DP_REQUEST_BW)) {
295654f7e554a9f Imre Deak 2024-02-26 1090 err = -EINVAL;
295654f7e554a9f Imre Deak 2024-02-26 1091 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1092 }
295654f7e554a9f Imre Deak 2024-02-26 1093
295654f7e554a9f Imre Deak 2024-02-26 1094 err = clear_bw_req_state(tunnel->aux);
295654f7e554a9f Imre Deak 2024-02-26 1095 if (err)
295654f7e554a9f Imre Deak 2024-02-26 1096 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1097
295654f7e554a9f Imre Deak 2024-02-26 1098 if (drm_dp_dpcd_writeb(tunnel->aux, DP_REQUEST_BW, request_bw) < 0) {
295654f7e554a9f Imre Deak 2024-02-26 1099 err = -EIO;
295654f7e554a9f Imre Deak 2024-02-26 1100 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1101 }
295654f7e554a9f Imre Deak 2024-02-26 1102
295654f7e554a9f Imre Deak 2024-02-26 1103 timeout = msecs_to_jiffies(3000);
295654f7e554a9f Imre Deak 2024-02-26 1104 add_wait_queue(&mgr->bw_req_queue, &wait);
295654f7e554a9f Imre Deak 2024-02-26 1105
295654f7e554a9f Imre Deak 2024-02-26 1106 for (;;) {
295654f7e554a9f Imre Deak 2024-02-26 1107 bool status_changed;
295654f7e554a9f Imre Deak 2024-02-26 1108
295654f7e554a9f Imre Deak 2024-02-26 1109 err = bw_req_complete(tunnel->aux, &status_changed);
295654f7e554a9f Imre Deak 2024-02-26 1110 if (err != -EAGAIN)
295654f7e554a9f Imre Deak 2024-02-26 1111 break;
295654f7e554a9f Imre Deak 2024-02-26 1112
295654f7e554a9f Imre Deak 2024-02-26 1113 if (status_changed) {
295654f7e554a9f Imre Deak 2024-02-26 1114 struct drm_dp_tunnel_regs regs;
295654f7e554a9f Imre Deak 2024-02-26 1115
295654f7e554a9f Imre Deak 2024-02-26 1116 err = read_and_verify_tunnel_regs(tunnel, ®s,
295654f7e554a9f Imre Deak 2024-02-26 1117 ALLOW_ALLOCATED_BW_CHANGE);
295654f7e554a9f Imre Deak 2024-02-26 1118 if (err)
295654f7e554a9f Imre Deak 2024-02-26 1119 break;
295654f7e554a9f Imre Deak 2024-02-26 1120 }
295654f7e554a9f Imre Deak 2024-02-26 1121
295654f7e554a9f Imre Deak 2024-02-26 1122 if (!timeout) {
295654f7e554a9f Imre Deak 2024-02-26 1123 err = -ETIMEDOUT;
295654f7e554a9f Imre Deak 2024-02-26 1124 break;
295654f7e554a9f Imre Deak 2024-02-26 1125 }
295654f7e554a9f Imre Deak 2024-02-26 1126
295654f7e554a9f Imre Deak 2024-02-26 1127 timeout = wait_woken(&wait, TASK_UNINTERRUPTIBLE, timeout);
295654f7e554a9f Imre Deak 2024-02-26 @1128 };
295654f7e554a9f Imre Deak 2024-02-26 1129
295654f7e554a9f Imre Deak 2024-02-26 1130 remove_wait_queue(&mgr->bw_req_queue, &wait);
295654f7e554a9f Imre Deak 2024-02-26 1131
295654f7e554a9f Imre Deak 2024-02-26 1132 if (err)
295654f7e554a9f Imre Deak 2024-02-26 1133 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1134
295654f7e554a9f Imre Deak 2024-02-26 1135 tunnel->allocated_bw = request_bw * tunnel->bw_granularity;
295654f7e554a9f Imre Deak 2024-02-26 1136
295654f7e554a9f Imre Deak 2024-02-26 1137 out:
295654f7e554a9f Imre Deak 2024-02-26 1138 tun_dbg_stat(tunnel, err, "Allocating %d/%d Mb/s for tunnel: Group alloc:%d/%d Mb/s",
295654f7e554a9f Imre Deak 2024-02-26 1139 DPTUN_BW_ARG(request_bw * tunnel->bw_granularity),
295654f7e554a9f Imre Deak 2024-02-26 1140 DPTUN_BW_ARG(get_max_tunnel_bw(tunnel)),
295654f7e554a9f Imre Deak 2024-02-26 1141 DPTUN_BW_ARG(group_allocated_bw(tunnel->group)),
295654f7e554a9f Imre Deak 2024-02-26 1142 DPTUN_BW_ARG(tunnel->group->available_bw));
295654f7e554a9f Imre Deak 2024-02-26 1143
295654f7e554a9f Imre Deak 2024-02-26 1144 if (err == -EIO)
295654f7e554a9f Imre Deak 2024-02-26 1145 drm_dp_tunnel_set_io_error(tunnel);
295654f7e554a9f Imre Deak 2024-02-26 1146
295654f7e554a9f Imre Deak 2024-02-26 1147 return err;
295654f7e554a9f Imre Deak 2024-02-26 1148 }
295654f7e554a9f Imre Deak 2024-02-26 1149
295654f7e554a9f Imre Deak 2024-02-26 1150 /**
295654f7e554a9f Imre Deak 2024-02-26 1151 * drm_dp_tunnel_alloc_bw - Allocate BW for a DP tunnel
295654f7e554a9f Imre Deak 2024-02-26 1152 * @tunnel: Tunnel object
295654f7e554a9f Imre Deak 2024-02-26 1153 * @bw: BW in kB/s units
295654f7e554a9f Imre Deak 2024-02-26 1154 *
295654f7e554a9f Imre Deak 2024-02-26 1155 * Allocate @bw kB/s for @tunnel. The allocated BW must be freed after use by
295654f7e554a9f Imre Deak 2024-02-26 1156 * calling this function for the same tunnel setting @bw to 0.
295654f7e554a9f Imre Deak 2024-02-26 1157 *
295654f7e554a9f Imre Deak 2024-02-26 1158 * Returns 0 in case of success, a negative error code otherwise.
295654f7e554a9f Imre Deak 2024-02-26 1159 */
295654f7e554a9f Imre Deak 2024-02-26 1160 int drm_dp_tunnel_alloc_bw(struct drm_dp_tunnel *tunnel, int bw)
295654f7e554a9f Imre Deak 2024-02-26 1161 {
295654f7e554a9f Imre Deak 2024-02-26 1162 int err;
295654f7e554a9f Imre Deak 2024-02-26 1163
295654f7e554a9f Imre Deak 2024-02-26 1164 err = check_tunnel(tunnel);
295654f7e554a9f Imre Deak 2024-02-26 1165 if (err)
295654f7e554a9f Imre Deak 2024-02-26 1166 return err;
295654f7e554a9f Imre Deak 2024-02-26 1167
295654f7e554a9f Imre Deak 2024-02-26 1168 return allocate_tunnel_bw(tunnel, bw);
295654f7e554a9f Imre Deak 2024-02-26 1169 }
295654f7e554a9f Imre Deak 2024-02-26 1170 EXPORT_SYMBOL(drm_dp_tunnel_alloc_bw);
295654f7e554a9f Imre Deak 2024-02-26 1171
295654f7e554a9f Imre Deak 2024-02-26 1172 /**
295654f7e554a9f Imre Deak 2024-02-26 1173 * drm_dp_tunnel_atomic_get_allocated_bw - Get the BW allocated for a DP tunnel
295654f7e554a9f Imre Deak 2024-02-26 1174 * @tunnel: Tunnel object
295654f7e554a9f Imre Deak 2024-02-26 1175 *
295654f7e554a9f Imre Deak 2024-02-26 1176 * Get the current BW allocated for @tunnel. After the tunnel is created /
295654f7e554a9f Imre Deak 2024-02-26 1177 * resumed and the BW allocation mode is enabled for it, the allocation
295654f7e554a9f Imre Deak 2024-02-26 1178 * becomes determined only after the first allocation request by the driver
295654f7e554a9f Imre Deak 2024-02-26 1179 * calling drm_dp_tunnel_alloc_bw().
295654f7e554a9f Imre Deak 2024-02-26 1180 *
295654f7e554a9f Imre Deak 2024-02-26 1181 * Return the BW allocated for the tunnel, or -1 if the allocation is
295654f7e554a9f Imre Deak 2024-02-26 1182 * undetermined.
295654f7e554a9f Imre Deak 2024-02-26 1183 */
295654f7e554a9f Imre Deak 2024-02-26 1184 int drm_dp_tunnel_get_allocated_bw(struct drm_dp_tunnel *tunnel)
295654f7e554a9f Imre Deak 2024-02-26 1185 {
295654f7e554a9f Imre Deak 2024-02-26 1186 return tunnel->allocated_bw;
295654f7e554a9f Imre Deak 2024-02-26 1187 }
295654f7e554a9f Imre Deak 2024-02-26 1188 EXPORT_SYMBOL(drm_dp_tunnel_get_allocated_bw);
295654f7e554a9f Imre Deak 2024-02-26 1189
295654f7e554a9f Imre Deak 2024-02-26 1190 /*
295654f7e554a9f Imre Deak 2024-02-26 1191 * Return 0 if the status hasn't changed, 1 if the status has changed, a
295654f7e554a9f Imre Deak 2024-02-26 1192 * negative error code in case of an I/O failure.
295654f7e554a9f Imre Deak 2024-02-26 1193 */
295654f7e554a9f Imre Deak 2024-02-26 1194 static int check_and_clear_status_change(struct drm_dp_tunnel *tunnel)
295654f7e554a9f Imre Deak 2024-02-26 1195 {
295654f7e554a9f Imre Deak 2024-02-26 1196 u8 mask = DP_BW_ALLOCATION_CAPABILITY_CHANGED | DP_ESTIMATED_BW_CHANGED;
295654f7e554a9f Imre Deak 2024-02-26 1197 u8 val;
295654f7e554a9f Imre Deak 2024-02-26 1198
295654f7e554a9f Imre Deak 2024-02-26 1199 if (drm_dp_dpcd_readb(tunnel->aux, DP_TUNNELING_STATUS, &val) < 0)
295654f7e554a9f Imre Deak 2024-02-26 1200 goto out_err;
295654f7e554a9f Imre Deak 2024-02-26 1201
295654f7e554a9f Imre Deak 2024-02-26 1202 val &= mask;
295654f7e554a9f Imre Deak 2024-02-26 1203
295654f7e554a9f Imre Deak 2024-02-26 1204 if (val) {
295654f7e554a9f Imre Deak 2024-02-26 1205 if (drm_dp_dpcd_writeb(tunnel->aux, DP_TUNNELING_STATUS, val) < 0)
295654f7e554a9f Imre Deak 2024-02-26 1206 goto out_err;
295654f7e554a9f Imre Deak 2024-02-26 1207
295654f7e554a9f Imre Deak 2024-02-26 1208 return 1;
295654f7e554a9f Imre Deak 2024-02-26 1209 }
295654f7e554a9f Imre Deak 2024-02-26 1210
295654f7e554a9f Imre Deak 2024-02-26 1211 if (!drm_dp_tunnel_bw_alloc_is_enabled(tunnel))
295654f7e554a9f Imre Deak 2024-02-26 1212 return 0;
295654f7e554a9f Imre Deak 2024-02-26 1213
295654f7e554a9f Imre Deak 2024-02-26 1214 /*
295654f7e554a9f Imre Deak 2024-02-26 1215 * Check for estimated BW changes explicitly to account for lost
295654f7e554a9f Imre Deak 2024-02-26 1216 * BW change notifications.
295654f7e554a9f Imre Deak 2024-02-26 1217 */
295654f7e554a9f Imre Deak 2024-02-26 1218 if (drm_dp_dpcd_readb(tunnel->aux, DP_ESTIMATED_BW, &val) < 0)
295654f7e554a9f Imre Deak 2024-02-26 1219 goto out_err;
295654f7e554a9f Imre Deak 2024-02-26 1220
295654f7e554a9f Imre Deak 2024-02-26 1221 if (val * tunnel->bw_granularity != tunnel->estimated_bw)
295654f7e554a9f Imre Deak 2024-02-26 1222 return 1;
295654f7e554a9f Imre Deak 2024-02-26 1223
295654f7e554a9f Imre Deak 2024-02-26 1224 return 0;
295654f7e554a9f Imre Deak 2024-02-26 1225
295654f7e554a9f Imre Deak 2024-02-26 1226 out_err:
295654f7e554a9f Imre Deak 2024-02-26 1227 drm_dp_tunnel_set_io_error(tunnel);
295654f7e554a9f Imre Deak 2024-02-26 1228
295654f7e554a9f Imre Deak 2024-02-26 1229 return -EIO;
295654f7e554a9f Imre Deak 2024-02-26 1230 }
295654f7e554a9f Imre Deak 2024-02-26 1231
295654f7e554a9f Imre Deak 2024-02-26 1232 /**
295654f7e554a9f Imre Deak 2024-02-26 1233 * drm_dp_tunnel_update_state - Update DP tunnel SW state with the HW state
295654f7e554a9f Imre Deak 2024-02-26 1234 * @tunnel: Tunnel object
295654f7e554a9f Imre Deak 2024-02-26 1235 *
295654f7e554a9f Imre Deak 2024-02-26 1236 * Update the SW state of @tunnel with the HW state.
295654f7e554a9f Imre Deak 2024-02-26 1237 *
295654f7e554a9f Imre Deak 2024-02-26 1238 * Returns 0 if the state has not changed, 1 if it has changed and got updated
295654f7e554a9f Imre Deak 2024-02-26 1239 * successfully and a negative error code otherwise.
295654f7e554a9f Imre Deak 2024-02-26 1240 */
295654f7e554a9f Imre Deak 2024-02-26 1241 int drm_dp_tunnel_update_state(struct drm_dp_tunnel *tunnel)
295654f7e554a9f Imre Deak 2024-02-26 1242 {
295654f7e554a9f Imre Deak 2024-02-26 1243 struct drm_dp_tunnel_regs regs;
295654f7e554a9f Imre Deak 2024-02-26 1244 bool changed = false;
295654f7e554a9f Imre Deak 2024-02-26 1245 int ret;
295654f7e554a9f Imre Deak 2024-02-26 1246
295654f7e554a9f Imre Deak 2024-02-26 1247 ret = check_tunnel(tunnel);
295654f7e554a9f Imre Deak 2024-02-26 1248 if (ret < 0)
295654f7e554a9f Imre Deak 2024-02-26 1249 return ret;
295654f7e554a9f Imre Deak 2024-02-26 1250
295654f7e554a9f Imre Deak 2024-02-26 1251 ret = check_and_clear_status_change(tunnel);
295654f7e554a9f Imre Deak 2024-02-26 1252 if (ret < 0)
295654f7e554a9f Imre Deak 2024-02-26 1253 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1254
295654f7e554a9f Imre Deak 2024-02-26 1255 if (!ret)
295654f7e554a9f Imre Deak 2024-02-26 1256 return 0;
295654f7e554a9f Imre Deak 2024-02-26 1257
295654f7e554a9f Imre Deak 2024-02-26 1258 ret = read_and_verify_tunnel_regs(tunnel, ®s, 0);
295654f7e554a9f Imre Deak 2024-02-26 1259 if (ret)
295654f7e554a9f Imre Deak 2024-02-26 1260 goto out;
295654f7e554a9f Imre Deak 2024-02-26 1261
295654f7e554a9f Imre Deak 2024-02-26 1262 if (update_dprx_caps(tunnel, ®s))
295654f7e554a9f Imre Deak 2024-02-26 1263 changed = true;
295654f7e554a9f Imre Deak 2024-02-26 1264
295654f7e554a9f Imre Deak 2024-02-26 1265 ret = update_group_available_bw(tunnel, ®s);
295654f7e554a9f Imre Deak 2024-02-26 1266 if (ret == 1)
295654f7e554a9f Imre Deak 2024-02-26 1267 changed = true;
295654f7e554a9f Imre Deak 2024-02-26 1268
295654f7e554a9f Imre Deak 2024-02-26 1269 out:
295654f7e554a9f Imre Deak 2024-02-26 @1270 tun_dbg_stat(tunnel, ret < 0 ? ret : 0,
295654f7e554a9f Imre Deak 2024-02-26 1271 "State update: Changed:%s DPRX:%dx%d Tunnel alloc:%d/%d Group alloc:%d/%d Mb/s",
295654f7e554a9f Imre Deak 2024-02-26 1272 str_yes_no(changed),
295654f7e554a9f Imre Deak 2024-02-26 1273 tunnel->max_dprx_rate / 100, tunnel->max_dprx_lane_count,
295654f7e554a9f Imre Deak 2024-02-26 1274 DPTUN_BW_ARG(tunnel->allocated_bw),
295654f7e554a9f Imre Deak 2024-02-26 1275 DPTUN_BW_ARG(get_max_tunnel_bw(tunnel)),
295654f7e554a9f Imre Deak 2024-02-26 1276 DPTUN_BW_ARG(group_allocated_bw(tunnel->group)),
295654f7e554a9f Imre Deak 2024-02-26 1277 DPTUN_BW_ARG(tunnel->group->available_bw));
295654f7e554a9f Imre Deak 2024-02-26 1278
295654f7e554a9f Imre Deak 2024-02-26 1279 if (ret < 0)
295654f7e554a9f Imre Deak 2024-02-26 1280 return ret;
295654f7e554a9f Imre Deak 2024-02-26 1281
295654f7e554a9f Imre Deak 2024-02-26 1282 if (changed)
295654f7e554a9f Imre Deak 2024-02-26 1283 return 1;
295654f7e554a9f Imre Deak 2024-02-26 1284
295654f7e554a9f Imre Deak 2024-02-26 1285 return 0;
295654f7e554a9f Imre Deak 2024-02-26 1286 }
295654f7e554a9f Imre Deak 2024-02-26 1287 EXPORT_SYMBOL(drm_dp_tunnel_update_state);
295654f7e554a9f Imre Deak 2024-02-26 1288
:::::: The code at line 1270 was first introduced by commit
:::::: 295654f7e554a9f089bdab0b2bb9a9aad7c402c0 drm/dp: Add support for DP tunneling
:::::: TO: Imre Deak <imre.deak@xxxxxxxxx>
:::::: CC: Imre Deak <imre.deak@xxxxxxxxx>
--
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