[PATCH v2 2/2] drm/bridge: anx7625: Add anx7625 MIPI DSI/DPI to DP bridge driver

[Dan Carpenter]

[  These are automated text from the 0-day bot -dan ]

Hi Xin,

Thank you for the patch! Perhaps something to improve:

url:    https://github.com/0day-ci/linux/commits/Xin-Ji/dt-bindings-drm-bridge-anx7625-MIPI-to-DP-transmitter-binding/20191014-043019

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp at intel.com>
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>

New smatch warnings:
drivers/gpu/drm/bridge/analogix/anx7625.c:1274 anx7625_start_dp_work() error: uninitialized symbol 'sp_tx_lane_count'.

# https://github.com/0day-ci/linux/commit/152a82b6747f10d6c13c7a422173947c2f2e1aa2
git remote add linux-review https://github.com/0day-ci/linux
git remote update linux-review
git checkout 152a82b6747f10d6c13c7a422173947c2f2e1aa2
vim +/sp_tx_lane_count +1274 drivers/gpu/drm/bridge/analogix/anx7625.c

152a82b6747f10 Xin Ji 2019-10-11  1253  static void anx7625_start_dp_work(struct anx7625_data *ctx)
152a82b6747f10 Xin Ji 2019-10-11  1254  {
152a82b6747f10 Xin Ji 2019-10-11  1255  	int ret;
152a82b6747f10 Xin Ji 2019-10-11  1256  	u8 buf[MAX_DPCD_BUFFER_SIZE];
152a82b6747f10 Xin Ji 2019-10-11  1257  	u8 hdcp_cap;
152a82b6747f10 Xin Ji 2019-10-11  1258  	struct device *dev = &ctx->client->dev;
152a82b6747f10 Xin Ji 2019-10-11  1259  	u8 sp_tx_bw; /* linktraining banwidth */
152a82b6747f10 Xin Ji 2019-10-11  1260  	u8 sp_tx_lane_count; /* link training lane count */
152a82b6747f10 Xin Ji 2019-10-11  1261  
152a82b6747f10 Xin Ji 2019-10-11  1262  	if (ctx->hpd_high_cnt >= 2) {
152a82b6747f10 Xin Ji 2019-10-11  1263  		DRM_DEV_DEBUG_DRIVER(dev, "anx7625 filter useless HPD\n");
152a82b6747f10 Xin Ji 2019-10-11  1264  		return;
152a82b6747f10 Xin Ji 2019-10-11  1265  	}
152a82b6747f10 Xin Ji 2019-10-11  1266  
152a82b6747f10 Xin Ji 2019-10-11  1267  	ctx->hpd_high_cnt++;
152a82b6747f10 Xin Ji 2019-10-11  1268  
152a82b6747f10 Xin Ji 2019-10-11  1269  	sp_tx_get_rx_bw(ctx, &sp_tx_bw);
152a82b6747f10 Xin Ji 2019-10-11  1270  
152a82b6747f10 Xin Ji 2019-10-11  1271  	sp_tx_aux_dpcdread_bytes(ctx, 0x00, 0x00, DPCD_MAX_LANE_COUNT,
152a82b6747f10 Xin Ji 2019-10-11  1272  				 1, &sp_tx_lane_count);
                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Smatch thinks sp_tx_aux_dpcdread_bytes() can fail and we don't check
for errors.

152a82b6747f10 Xin Ji 2019-10-11  1273  
152a82b6747f10 Xin Ji 2019-10-11 @1274  	sp_tx_lane_count = sp_tx_lane_count & 0x1f;
152a82b6747f10 Xin Ji 2019-10-11  1275  	sp_tx_aux_dpcdread_bytes(ctx, 0x06, 0x80, 0x28, 1, buf);/* read Bcap */
152a82b6747f10 Xin Ji 2019-10-11  1276  
152a82b6747f10 Xin Ji 2019-10-11  1277  	hdcp_cap = buf[0] & 0x01;
152a82b6747f10 Xin Ji 2019-10-11  1278  

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