From 4e17deac29d497cde8e28e8f24f663b46c4cd27c Mon Sep 17 00:00:00 2001
From: Avery Pennarun <apenwarr@gmail.com>
Date: Fri, 25 Apr 2014 08:03:01 -0400
Subject: [PATCH] mwifiex: add /sys/kernel/debug/mwifiex/*/crash, to simulate
 crashes.

For our first test case, just simulate a device disconnect/reconnect to make
it easier to check this code for race conditions, null pointers, etc.
---
 drivers/net/wireless/mwifiex/debugfs.c | 38 ++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/net/wireless/mwifiex/debugfs.c b/drivers/net/wireless/mwifiex/debugfs.c
index b8a49aa..a3c0678 100644
--- a/drivers/net/wireless/mwifiex/debugfs.c
+++ b/drivers/net/wireless/mwifiex/debugfs.c
@@ -669,6 +669,42 @@ done:
 	return ret;
 }
 
+/*
+ * Proc crash write handler.
+ *
+ * This function is called when the 'crash' file is opened for writing.
+ *
+ * Write a '1' to this file to simulate a device disconnect/reconnect.  In
+ * the future, other numbers may be used to simulate different kinds of
+ * crashes.
+ */
+static ssize_t
+mwifiex_crash_write(struct file *file,
+		       const char __user *ubuf, size_t count, loff_t *ppos)
+{
+	struct mwifiex_private *priv =
+		(struct mwifiex_private *) file->private_data;
+	char buf[16];
+	int mode;
+
+	memset(buf, 0, sizeof(buf));
+	if (simple_write_to_buffer(buf, sizeof(buf) - 1, ppos, ubuf, count) < 0) {
+		return -EFAULT;
+	}
+
+	mode = simple_strtol(buf, NULL, 0);
+	*ppos += count;
+	switch (mode) {
+	case 1:
+		pr_warn("causing crash: disconnect/reconnect");
+		priv->adapter->if_ops.card_reset(priv->adapter);
+		break;
+	default:
+		return -EIO;
+	}
+
+	return count;
+}
 
 #define MWIFIEX_DFS_ADD_FILE(name) do {                                 \
 	if (!debugfs_create_file(#name, 0644, priv->dfs_dev_dir,        \
@@ -701,6 +737,7 @@ MWIFIEX_DFS_FILE_READ_OPS(debug);
 MWIFIEX_DFS_FILE_READ_OPS(getlog);
 MWIFIEX_DFS_FILE_OPS(regrdwr);
 MWIFIEX_DFS_FILE_OPS(rdeeprom);
+MWIFIEX_DFS_FILE_WRITE_OPS(crash);
 
 /*
  * This function creates the debug FS directory structure and the files.
@@ -722,6 +759,7 @@ mwifiex_dev_debugfs_init(struct mwifiex_private *priv)
 	MWIFIEX_DFS_ADD_FILE(getlog);
 	MWIFIEX_DFS_ADD_FILE(regrdwr);
 	MWIFIEX_DFS_ADD_FILE(rdeeprom);
+	MWIFIEX_DFS_ADD_FILE(crash);
 }
 
 /*
-- 
1.9.1.423.g4596e3a