2 files changed, 91 insertions, 7 deletions

diff --git a/drivers/misc/ti-st/st_core.c b/drivers/misc/ti-st/st_core.c
index f7bb96f3a424..dd2c879faff6 100644
--- a/drivers/misc/ti-st/st_core.c
+++ b/drivers/misc/ti-st/st_core.c
@@ -52,6 +52,24 @@ static void remove_channel_from_table(struct st_data_s *st_gdata,
 	st_gdata->list[proto->chnl_id] = NULL;
 }
 
+/*
+ * called from KIM during firmware download.
+ *
+ * This is a wrapper function to tty->ops->write_room.
+ * It returns number of free space available in
+ * uart tx buffer.
+ */
+int st_get_uart_wr_room(struct st_data_s *st_gdata)
+{
+	struct tty_struct *tty;
+	if (unlikely(st_gdata == NULL || st_gdata->tty == NULL)) {
+		pr_err("tty unavailable to perform write");
+		return -1;
+	}
+	tty = st_gdata->tty;
+	return tty->ops->write_room(tty);
+}
+
 /* can be called in from
  * -- KIM (during fw download)
  * -- ST Core (during st_write)
diff --git a/drivers/misc/ti-st/st_kim.c b/drivers/misc/ti-st/st_kim.c
index ccc46a7b0abb..2c096ccd53b0 100644
--- a/drivers/misc/ti-st/st_kim.c
+++ b/drivers/misc/ti-st/st_kim.c
@@ -232,6 +232,26 @@ static long read_local_version(struct kim_data_s *kim_gdata, char *bts_scr_name)
 	return 0;
 }
 
+void skip_change_remote_baud(unsigned char **ptr, long *len)
+{
+	unsigned char *nxt_action, *cur_action;
+	cur_action = *ptr;
+
+	nxt_action = cur_action + sizeof(struct bts_action) +
+		((struct bts_action *) cur_action)->size;
+
+	if (((struct bts_action *) nxt_action)->type != ACTION_WAIT_EVENT) {
+		pr_err("invalid action after change remote baud command");
+	} else {
+		*ptr = *ptr + sizeof(struct bts_action) +
+			((struct bts_action *)nxt_action)->size;
+		*len = *len - (sizeof(struct bts_action) +
+				((struct bts_action *)nxt_action)->size);
+		/* warn user on not commenting these in firmware */
+		pr_warn("skipping the wait event of change remote baud");
+	}
+}
+
 /**
  * download_firmware -
  *	internal function which parses through the .bts firmware
@@ -244,6 +264,9 @@ static long download_firmware(struct kim_data_s *kim_gdata)
 	unsigned char *ptr = NULL;
 	unsigned char *action_ptr = NULL;
 	unsigned char bts_scr_name[30] = { 0 };	/* 30 char long bts scr name? */
+	int wr_room_space;
+	int cmd_size;
+	unsigned long timeout;
 
 	err = read_local_version(kim_gdata, bts_scr_name);
 	if (err != 0) {
@@ -280,13 +303,43 @@ static long download_firmware(struct kim_data_s *kim_gdata)
 			     0xFF36)) {
 				/* ignore remote change
 				 * baud rate HCI VS command */
-				pr_err
-				    (" change remote baud"
+				pr_warn("change remote baud"
 				    " rate command in firmware");
+				skip_change_remote_baud(&ptr, &len);
 				break;
 			}
+			/*
+			 * Make sure we have enough free space in uart
+			 * tx buffer to write current firmware command
+			 */
+			cmd_size = ((struct bts_action *)ptr)->size;
+			timeout = jiffies + msecs_to_jiffies(CMD_WR_TIME);
+			do {
+				wr_room_space =
+					st_get_uart_wr_room(kim_gdata->core_data);
+				if (wr_room_space < 0) {
+					pr_err("Unable to get free "
+							"space info from uart tx buffer");
+					release_firmware(kim_gdata->fw_entry);
+					return wr_room_space;
+				}
+				mdelay(1); /* wait 1ms before checking room */
+			} while ((wr_room_space < cmd_size) &&
+					time_before(jiffies, timeout));
+
+			/* Timeout happened ? */
+			if (time_after_eq(jiffies, timeout)) {
+				pr_err("Timeout while waiting for free "
+						"free space in uart tx buffer");
+				release_firmware(kim_gdata->fw_entry);
+				return -ETIMEDOUT;
+			}
 
-			INIT_COMPLETION(kim_gdata->kim_rcvd);
+			/*
+			 * Free space found in uart buffer, call st_int_write
+			 * to send current firmware command to the uart tx
+			 * buffer.
+			 */
 			err = st_int_write(kim_gdata->core_data,
 			((struct bts_action_send *)action_ptr)->data,
 					   ((struct bts_action *)ptr)->size);
@@ -294,15 +347,28 @@ static long download_firmware(struct kim_data_s *kim_gdata)
 				release_firmware(kim_gdata->fw_entry);
 				return err;
 			}
+			/*
+			 * Check number of bytes written to the uart tx buffer
+			 * and requested command write size
+			 */
+			if (err != cmd_size) {
+				pr_err("Number of bytes written to uart "
+						"tx buffer are not matching with "
+						"requested cmd write size");
+				release_firmware(kim_gdata->fw_entry);
+				return -EIO;
+			}
+			break;
+		case ACTION_WAIT_EVENT:  /* wait */
 			if (!wait_for_completion_timeout
-			    (&kim_gdata->kim_rcvd,
-			     msecs_to_jiffies(CMD_RESP_TIME))) {
-				pr_err
-				    (" response timeout during fw download ");
+					(&kim_gdata->kim_rcvd,
+					 msecs_to_jiffies(CMD_RESP_TIME))) {
+				pr_err("response timeout during fw download ");
 				/* timed out */
 				release_firmware(kim_gdata->fw_entry);
 				return -ETIMEDOUT;
 			}
+			INIT_COMPLETION(kim_gdata->kim_rcvd);
 			break;
 		case ACTION_DELAY:	/* sleep */
 			pr_info("sleep command in scr");