HID: bt: Wait for ACK on Sent Reports

Wait for an ACK from the device before returning from
hidp_output_raw_report(). This way, failures can be returned to the user
application. Also, it prevents ACK/NAK packets from an output packet from
being confused with ACK/NAK packets from an input request packet.

Signed-off-by: Alan Ott <alan@signal11.us>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 55 insertions, 3 deletions

diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
index 67cc4bc82c6..5383e6c7d09 100644
--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -316,6 +316,9 @@ static int hidp_send_report(struct hidp_session *session, struct hid_report *rep
 static int hidp_output_raw_report(struct hid_device *hid, unsigned char *data, size_t count,
                 unsigned char report_type)
 {
+        struct hidp_session *session = hid->driver_data;
+        int ret;
+
         switch (report_type) {
         case HID_FEATURE_REPORT:
                 report_type = HIDP_TRANS_SET_REPORT | HIDP_DATA_RTYPE_FEATURE;
@@ -327,10 +330,47 @@ static int hidp_output_raw_report(struct hid_device *hid, unsigned char *data, s
                 return -EINVAL;
         }
 
+        if (mutex_lock_interruptible(&session->report_mutex))
+                return -ERESTARTSYS;
+
+        /* Set up our wait, and send the report request to the device. */
+        set_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
         if (hidp_send_ctrl_message(hid->driver_data, report_type,
-                        data, count))
-                return -ENOMEM;
-        return count;
+                        data, count)) {
+                ret = -ENOMEM;
+                goto err;
+        }
+
+        /* Wait for the ACK from the device. */
+        while (test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags)) {
+                int res;
+
+                res = wait_event_interruptible_timeout(session->report_queue,
+                        !test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags),
+                        10*HZ);
+                if (res == 0) {
+                        /* timeout */
+                        ret = -EIO;
+                        goto err;
+                }
+                if (res < 0) {
+                        /* signal */
+                        ret = -ERESTARTSYS;
+                        goto err;
+                }
+        }
+
+        if (!session->output_report_success) {
+                ret = -EIO;
+                goto err;
+        }
+
+        ret = count;
+
+err:
+        clear_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
+        mutex_unlock(&session->report_mutex);
+        return ret;
 }
 
 static void hidp_idle_timeout(unsigned long arg)
@@ -357,10 +397,12 @@ static void hidp_process_handshake(struct hidp_session *session,
                                         unsigned char param)
 {
         BT_DBG("session %p param 0x%02x", session, param);
+        session->output_report_success = 0; /* default condition */
 
         switch (param) {
         case HIDP_HSHK_SUCCESSFUL:
                 /* FIXME: Call into SET_ GET_ handlers here */
+                session->output_report_success = 1;
                 break;
 
         case HIDP_HSHK_NOT_READY:
@@ -385,6 +427,12 @@ static void hidp_process_handshake(struct hidp_session *session,
                         HIDP_TRANS_HANDSHAKE | HIDP_HSHK_ERR_INVALID_PARAMETER, NULL, 0);
                 break;
         }
+
+        /* Wake up the waiting thread. */
+        if (test_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags)) {
+                clear_bit(HIDP_WAITING_FOR_SEND_ACK, &session->flags);
+                wake_up_interruptible(&session->report_queue);
+        }
 }
 
 static void hidp_process_hid_control(struct hidp_session *session,
diff --git a/net/bluetooth/hidp/hidp.h b/net/bluetooth/hidp/hidp.h
index 2cc35dc8fa0..92e093e61f2 100644
--- a/net/bluetooth/hidp/hidp.h
+++ b/net/bluetooth/hidp/hidp.h
@@ -80,6 +80,7 @@
 #define HIDP_VIRTUAL_CABLE_UNPLUG       0
 #define HIDP_BOOT_PROTOCOL_MODE         1
 #define HIDP_BLUETOOTH_VENDOR_ID        9
+#define HIDP_WAITING_FOR_SEND_ACK       11
 
 struct hidp_connadd_req {
         int   ctrl_sock;        // Connected control socket
@@ -154,6 +155,9 @@ struct hidp_session {
         struct sk_buff_head ctrl_transmit;
         struct sk_buff_head intr_transmit;
 
+        /* Used in hidp_output_raw_report() */
+        int output_report_success; /* boolean */
+
         /* Report descriptor */
         __u8 *rd_data;
         uint rd_size;