slim: msm: Improve bulk message timeout error handling

If a bulk message times out due to interrupt starvation, a late
coming interrupt may access structures that are not valid.
Improve timeout error handling by resetting variables, and changing
relevant logging.

Change-Id: Ie0ee2fd9c2ce1628c69e1975fe713a2a26d9e716
Signed-off-by: Sagar Dharia <sdharia@codeaurora.org>

2 files changed, 29 insertions, 33 deletions

diff --git a/drivers/slimbus/slim-msm-ngd.c b/drivers/slimbus/slim-msm-ngd.c
index c529e221f68e..7cb2dcef80ef 100644
--- a/drivers/slimbus/slim-msm-ngd.c
+++ b/drivers/slimbus/slim-msm-ngd.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2015, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2016, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -284,6 +284,21 @@ static int ngd_get_tid(struct slim_controller *ctrl, struct slim_msg_txn *txn,
 	spin_unlock_irqrestore(&ctrl->txn_lock, flags);
 	return 0;
 }
+
+static void slim_reinit_tx_msgq(struct msm_slim_ctrl *dev)
+{
+	/*
+	 * disconnect/recoonect pipe so that subsequent
+	 * transactions don't timeout due to unavailable
+	 * descriptors
+	 */
+	if (dev->state != MSM_CTRL_DOWN) {
+		msm_slim_disconnect_endp(dev, &dev->tx_msgq,
+					&dev->use_tx_msgqs);
+		msm_slim_connect_endp(dev, &dev->tx_msgq);
+	}
+}
+
 static int ngd_xfer_msg(struct slim_controller *ctrl, struct slim_msg_txn *txn)
 {
 	DECLARE_COMPLETION_ONSTACK(done);
@@ -570,19 +585,7 @@ static int ngd_xfer_msg(struct slim_controller *ctrl, struct slim_msg_txn *txn)
 							i, *(pbuf + i));
 			if (idx < MSM_TX_BUFS)
 				dev->wr_comp[idx] = NULL;
-			/*
-			 * disconnect/recoonect pipe so that subsequent
-			 * transactions don't timeout due to unavailable
-			 * descriptors
-			 */
-			if (dev->state != MSM_CTRL_DOWN) {
-				/* print BAM debug info for TX pipe */
-				sps_get_bam_debug_info(dev->bam.hdl, 93,
-							SPS_BAM_PIPE(4), 0, 2);
-				msm_slim_disconnect_endp(dev, &dev->tx_msgq,
-							&dev->use_tx_msgqs);
-				msm_slim_connect_endp(dev, &dev->tx_msgq);
-			}
+			slim_reinit_tx_msgq(dev);
 		} else if (!timeout) {
 			ret = -ETIMEDOUT;
 			SLIM_WARN(dev, "timeout non-BAM TX,len:%d", txn->rl);
@@ -791,11 +794,6 @@ static int ngd_bulk_wr(struct slim_controller *ctrl, u8 la, u8 mt, u8 mc,
 		}
 	}
 	header = dev->bulk.base;
-	/* SLIM_INFO only prints to internal buffer log, does not do pr_info */
-	for (i = 0; i < (dev->bulk.size); i += 16, header += 4)
-		SLIM_INFO(dev, "bulk sz:%d:0x%x, 0x%x, 0x%x, 0x%x",
-			  dev->bulk.size, *header, *(header+1), *(header+2),
-			  *(header+3));
 	if (comp_cb) {
 		dev->bulk.cb = comp_cb;
 		dev->bulk.ctx = ctx;
@@ -827,8 +825,12 @@ static int ngd_bulk_wr(struct slim_controller *ctrl, u8 la, u8 mt, u8 mc,
 		}
 	}
 retpath:
-	if (ret)
+	if (ret) {
 		dev->bulk.in_progress = false;
+		dev->bulk.ctx = NULL;
+		dev->bulk.wr_dma = 0;
+		slim_reinit_tx_msgq(dev);
+	}
 	mutex_unlock(&dev->tx_lock);
 	msm_slim_put_ctrl(dev);
 	return ret;
diff --git a/drivers/slimbus/slim-msm.c b/drivers/slimbus/slim-msm.c
index e17a5c7857b8..1ca5109615fe 100644
--- a/drivers/slimbus/slim-msm.c
+++ b/drivers/slimbus/slim-msm.c
@@ -531,7 +531,6 @@ void msm_slim_tx_msg_return(struct msm_slim_ctrl *dev, int err)
 			return;
 		}
 		if (addr == dev->bulk.wr_dma) {
-			SLIM_INFO(dev, "BULK WR complete");
 			dma_unmap_single(dev->dev, dev->bulk.wr_dma,
 					 dev->bulk.size, DMA_TO_DEVICE);
 			if (!dev->bulk.cb)
@@ -541,20 +540,19 @@ void msm_slim_tx_msg_return(struct msm_slim_ctrl *dev, int err)
 			dev->bulk.in_progress = false;
 			pm_runtime_mark_last_busy(dev->dev);
 			return;
+		} else if (addr < mem->phys_base ||
+			   (addr > (mem->phys_base +
+				    (MSM_TX_BUFS * SLIM_MSGQ_BUF_LEN)))) {
+			SLIM_WARN(dev, "BUF out of bounds:base:0x%pa, io:0x%pa",
+					&mem->phys_base, &addr);
+			continue;
 		}
 		idx = (int) ((addr - mem->phys_base)
 			/ SLIM_MSGQ_BUF_LEN);
-		if (idx < MSM_TX_BUFS && dev->wr_comp[idx]) {
+		if (dev->wr_comp[idx]) {
 			struct completion *comp = dev->wr_comp[idx];
 			dev->wr_comp[idx] = NULL;
 			complete(comp);
-		} else if (idx >= MSM_TX_BUFS) {
-			SLIM_ERR(dev, "BUF out of bounds:base:0x%pa, io:0x%pa",
-					&mem->phys_base, &addr);
-			/* print BAM debug info for TX pipe */
-			sps_get_bam_debug_info(dev->bam.hdl, 93,
-						SPS_BAM_PIPE(4), 0, 2);
-			continue;
 		}
 		if (err) {
 			int i;
@@ -563,10 +561,6 @@ void msm_slim_tx_msg_return(struct msm_slim_ctrl *dev, int err)
 			/* print the descriptor that resulted in error */
 			for (i = 0; i < (SLIM_MSGQ_BUF_LEN >> 2); i++)
 				SLIM_WARN(dev, "err desc[%d]:0x%x", i, addr[i]);
-			/* print BAM debug info for TX pipe for invalid TX */
-			if (err == -EINVAL)
-				sps_get_bam_debug_info(dev->bam.hdl, 93,
-							SPS_BAM_PIPE(4), 0, 2);
 		}
 		/* reclaim all packets that were delivered out of order */
 		if (idx != dev->tx_head)