iwlwifi: improve the reports in TX path

Also when things go wrong (queues don't get emtpy), try to
get some data from the HW.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/pcie/trans.c b/drivers/net/wireless/iwlwifi/pcie/trans.c
index 59340ff..c57641e 100644
--- a/drivers/net/wireless/iwlwifi/pcie/trans.c
+++ b/drivers/net/wireless/iwlwifi/pcie/trans.c
@@ -890,6 +890,8 @@
 	struct iwl_queue *q;
 	int cnt;
 	unsigned long now = jiffies;
+	u32 scd_sram_addr;
+	u8 buf[16];
 	int ret = 0;
 
 	/* waiting for all the tx frames complete might take a while */
@@ -903,11 +905,50 @@
 			msleep(1);
 
 		if (q->read_ptr != q->write_ptr) {
-			IWL_ERR(trans, "fail to flush all tx fifo queues\n");
+			IWL_ERR(trans,
+				"fail to flush all tx fifo queues Q %d\n", cnt);
 			ret = -ETIMEDOUT;
 			break;
 		}
 	}
+
+	if (!ret)
+		return 0;
+
+	IWL_ERR(trans, "Current SW read_ptr %d write_ptr %d\n",
+		txq->q.read_ptr, txq->q.write_ptr);
+
+	scd_sram_addr = trans_pcie->scd_base_addr +
+			SCD_TX_STTS_QUEUE_OFFSET(txq->q.id);
+	iwl_trans_read_mem_bytes(trans, scd_sram_addr, buf, sizeof(buf));
+
+	iwl_print_hex_error(trans, buf, sizeof(buf));
+
+	for (cnt = 0; cnt < FH_TCSR_CHNL_NUM; cnt++)
+		IWL_ERR(trans, "FH TRBs(%d) = 0x%08x\n", cnt,
+			iwl_read_direct32(trans, FH_TX_TRB_REG(cnt)));
+
+	for (cnt = 0; cnt < trans->cfg->base_params->num_of_queues; cnt++) {
+		u32 status = iwl_read_prph(trans, SCD_QUEUE_STATUS_BITS(cnt));
+		u8 fifo = (status >> SCD_QUEUE_STTS_REG_POS_TXF) & 0x7;
+		bool active = !!(status & BIT(SCD_QUEUE_STTS_REG_POS_ACTIVE));
+		u32 tbl_dw =
+			iwl_trans_read_mem32(trans, trans_pcie->scd_base_addr +
+					     SCD_TRANS_TBL_OFFSET_QUEUE(cnt));
+
+		if (cnt & 0x1)
+			tbl_dw = (tbl_dw & 0xFFFF0000) >> 16;
+		else
+			tbl_dw = tbl_dw & 0x0000FFFF;
+
+		IWL_ERR(trans,
+			"Q %d is %sactive and mapped to fifo %d ra_tid 0x%04x [%d,%d]\n",
+			cnt, active ? "" : "in", fifo, tbl_dw,
+			iwl_read_prph(trans,
+				      SCD_QUEUE_RDPTR(cnt)) & (txq->q.n_bd - 1),
+			iwl_read_prph(trans, SCD_QUEUE_WRPTR(cnt)));
+	}
+
 	return ret;
 }