Merge "diag: Add sysfs parameter to control diag mask clear"

4 files changed, 36 insertions, 7 deletions

diff --git a/drivers/char/diag/diag_usb.c b/drivers/char/diag/diag_usb.c
index ca54b24ec604..0a0fc4400de5 100644
--- a/drivers/char/diag/diag_usb.c
+++ b/drivers/char/diag/diag_usb.c
@@ -14,6 +14,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/device.h>
+#include <linux/kernel.h>
 #include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/ratelimit.h>
@@ -218,7 +219,8 @@ static void usb_disconnect(struct diag_usb_info *ch)
 	if (!ch)
 		return;
 
-	if (!atomic_read(&ch->connected) && driver->usb_connected)
+	if (!atomic_read(&ch->connected) &&
+		driver->usb_connected && diag_mask_param())
 		diag_clear_masks(NULL);
 
 	if (ch && ch->ops && ch->ops->close)
diff --git a/drivers/char/diag/diagchar.h b/drivers/char/diag/diagchar.h
index 67db49badf21..1488f9dc4300 100644
--- a/drivers/char/diag/diagchar.h
+++ b/drivers/char/diag/diagchar.h
@@ -632,6 +632,7 @@ void diag_cmd_remove_reg(struct diag_cmd_reg_entry_t *entry, uint8_t proc);
 void diag_cmd_remove_reg_by_pid(int pid);
 void diag_cmd_remove_reg_by_proc(int proc);
 int diag_cmd_chk_polling(struct diag_cmd_reg_entry_t *entry);
+int diag_mask_param(void);
 void diag_clear_masks(struct diag_md_session_t *info);
 
 void diag_record_stats(int type, int flag);
diff --git a/drivers/char/diag/diagchar_core.c b/drivers/char/diag/diagchar_core.c
index 76559633f387..9494314d18f0 100644
--- a/drivers/char/diag/diagchar_core.c
+++ b/drivers/char/diag/diagchar_core.c
@@ -144,6 +144,14 @@ module_param(max_clients, uint, 0);
 static struct timer_list drain_timer;
 static int timer_in_progress;
 
+/*
+ * Diag Mask clear variable
+ * Used for clearing masks upon
+ * USB disconnection and stopping ODL
+ */
+static int diag_mask_clear_param = 1;
+module_param(diag_mask_clear_param, int, 0644);
+
 struct diag_apps_data_t {
 	void *buf;
 	uint32_t len;
@@ -390,7 +398,10 @@ static uint32_t diag_translate_kernel_to_user_mask(uint32_t peripheral_mask)
 
 	return ret;
 }
-
+int diag_mask_param(void)
+{
+	return diag_mask_clear_param;
+}
 void diag_clear_masks(struct diag_md_session_t *info)
 {
 	int ret;
@@ -423,7 +434,8 @@ static void diag_close_logging_process(const int pid)
 	if (!session_info)
 		return;
 
-	diag_clear_masks(session_info);
+	if (diag_mask_clear_param)
+		diag_clear_masks(session_info);
 
 	mutex_lock(&driver->diag_maskclear_mutex);
 	driver->mask_clear = 1;
diff --git a/drivers/char/diag/diagfwd.c b/drivers/char/diag/diagfwd.c
index 876b455624b2..a7069bc0edf3 100644
--- a/drivers/char/diag/diagfwd.c
+++ b/drivers/char/diag/diagfwd.c
@@ -1232,6 +1232,8 @@ static int diagfwd_mux_open(int id, int mode)
 
 static int diagfwd_mux_close(int id, int mode)
 {
+	uint8_t i;
+
 	switch (mode) {
 	case DIAG_USB_MODE:
 		driver->usb_connected = 0;
@@ -1252,10 +1254,22 @@ static int diagfwd_mux_close(int id, int mode)
 		 */
 	} else {
 		/*
-		* With clearing of masks on ODL exit and
-		* USB disconnection, closing of the channel is
-		* not needed.This enables read and drop of stale packets.
-		*/
+		 * With sysfs parameter to clear masks set,
+		 * peripheral masks are cleared on ODL exit and
+		 * USB disconnection and buffers are not marked busy.
+		 * This enables read and drop of stale packets.
+		 *
+		 * With sysfs parameter to clear masks cleared,
+		 * masks are not cleared and buffers are to be marked
+		 * busy to ensure traffic generated by peripheral
+		 * are not read
+		 */
+		if (!(diag_mask_param())) {
+			for (i = 0; i < NUM_PERIPHERALS; i++) {
+				diagfwd_close(i, TYPE_DATA);
+				diagfwd_close(i, TYPE_CMD);
+			}
+		}
 		/* Re enable HDLC encoding */
 		pr_debug("diag: In %s, re-enabling HDLC encoding\n",
 		       __func__);