Fixed standalone locking bugs in HID host idle get/set (#264)

Two issues discovered while reviewing and fixing thread-safety issues in
the new ux_host_class_hid_protocol_get/set functions (PR #244).

1. idle_get.c: wrong operator acquires no lock in standalone mode

   Line 104 used '&= ~UX_HOST_CLASS_HID_FLAG_LOCK' (the release/clear
   operation) instead of '|= UX_HOST_CLASS_HID_FLAG_LOCK' (acquire/set).
   The preceding check correctly returns UX_BUSY when the flag is set,
   but the follow-on line then immediately clears it instead of setting it.
   The net effect is that the HID instance is never actually locked in
   UX_HOST_STANDALONE mode, making the mutual-exclusion check a no-op.

2. idle_set.c: standalone path used a blocking spin-loop

   The standalone branch called _ux_host_class_hid_idle_set_run() in a
   do/while loop, blocking the caller until the transfer completed. This
   is inconsistent with every other inline HID control-transfer function
   (idle_get, report_get, report_set, protocol_get, protocol_set) which
   all use the direct UX_DISABLE/UX_RESTORE atomic flag pattern and
   return UX_BUSY if the instance or device endpoint is already locked.

   Replaced with the same inline standalone locking pattern used by the
   other functions: atomic HID FLAG_LOCK acquire, atomic DEVICE_FLAG_LOCK
   acquire with AUTO_DEVICE_UNLOCK + UX_TRANSFER_STATE_RESET, and an
   AUTO_WAIT check at completion consistent with idle_get behavior.

Co-authored-by: Copilot <[email protected]>

2 files changed, 35 insertions, 16 deletions

diff --git a/common/usbx_host_classes/src/ux_host_class_hid_idle_get.c b/common/usbx_host_classes/src/ux_host_class_hid_idle_get.c
index e120884..e39f988 100644
--- a/common/usbx_host_classes/src/ux_host_class_hid_idle_get.c
+++ b/common/usbx_host_classes/src/ux_host_class_hid_idle_get.c
@@ -101,7 +101,7 @@ UINT            status;
         UX_RESTORE
         return(UX_BUSY);
     }
-    hid -> ux_host_class_hid_flags &= ~UX_HOST_CLASS_HID_FLAG_LOCK;
+    hid -> ux_host_class_hid_flags |= UX_HOST_CLASS_HID_FLAG_LOCK;
     UX_RESTORE
 #else
 
diff --git a/common/usbx_host_classes/src/ux_host_class_hid_idle_set.c b/common/usbx_host_classes/src/ux_host_class_hid_idle_set.c
index fe74deb..1611e91 100644
--- a/common/usbx_host_classes/src/ux_host_class_hid_idle_set.c
+++ b/common/usbx_host_classes/src/ux_host_class_hid_idle_set.c
@@ -69,14 +69,8 @@
 UINT  _ux_host_class_hid_idle_set(UX_HOST_CLASS_HID *hid, USHORT idle_time, USHORT report_id)
 {
 #if defined(UX_HOST_STANDALONE)
-UINT            status;
-    do
-    {
-        status = _ux_host_class_hid_idle_set_run(hid, idle_time, report_id);
-    } while(status == UX_STATE_WAIT || status == UX_STATE_LOCK);
-    return(hid -> ux_host_class_hid_status);
-#else
-
+UX_INTERRUPT_SAVE_AREA
+#endif
 UX_ENDPOINT     *control_endpoint;
 UX_TRANSFER     *transfer_request;
 UINT            status;
@@ -99,6 +93,16 @@ UINT            status;
     transfer_request =  &control_endpoint -> ux_endpoint_transfer_request;
 
     /* Protect thread reentry to this instance.  */
+#if defined(UX_HOST_STANDALONE)
+    UX_DISABLE
+    if (hid -> ux_host_class_hid_flags & UX_HOST_CLASS_HID_FLAG_LOCK)
+    {
+        UX_RESTORE
+        return(UX_BUSY);
+    }
+    hid -> ux_host_class_hid_flags |= UX_HOST_CLASS_HID_FLAG_LOCK;
+    UX_RESTORE
+#else
     status =  _ux_host_semaphore_get(&hid -> ux_host_class_hid_semaphore, UX_WAIT_FOREVER);
     if (status != UX_SUCCESS)
         return(status);
@@ -106,17 +110,27 @@ UINT            status;
     /* Protect the control endpoint semaphore here.  It will be unprotected in the
        transfer request function.  */
     status =  _ux_host_semaphore_get(&hid -> ux_host_class_hid_device -> ux_device_protection_semaphore, UX_WAIT_FOREVER);
-
-    /* Check for status.  */
     if (status != UX_SUCCESS)
     {
-
-        /* Something went wrong. */
-        /* Unprotect thread reentry to this instance.  */
         _ux_host_semaphore_put(&hid -> ux_host_class_hid_semaphore);
-
         return(status);
     }
+#endif
+
+#if defined(UX_HOST_STANDALONE)
+    /* Protect the control endpoint.  It will be unprotected in the transfer request function.  */
+    UX_DISABLE
+    if (hid -> ux_host_class_hid_device -> ux_device_flags & UX_DEVICE_FLAG_LOCK)
+    {
+        _ux_host_class_hid_unlock(hid);
+        UX_RESTORE
+        return(UX_BUSY);
+    }
+    hid -> ux_host_class_hid_device -> ux_device_flags |=  UX_DEVICE_FLAG_LOCK;
+    transfer_request -> ux_transfer_request_flags |=  UX_TRANSFER_FLAG_AUTO_DEVICE_UNLOCK;
+    UX_TRANSFER_STATE_RESET(transfer_request);
+    UX_RESTORE
+#endif
 
     /* Create a transfer request for the SET_IDLE request.  */
     transfer_request -> ux_transfer_request_data_pointer =      UX_NULL;
@@ -129,12 +143,17 @@ UINT            status;
     /* Send request to HCD layer.  */
     status =  _ux_host_stack_transfer_request(transfer_request);
 
+#if defined(UX_HOST_STANDALONE)
+    if (!(transfer_request -> ux_transfer_request_flags & UX_TRANSFER_FLAG_AUTO_WAIT))
+        return(status);
+    _ux_host_class_hid_unlock(hid);
+#else
     /* Unprotect thread reentry to this instance.  */
     _ux_host_semaphore_put(&hid -> ux_host_class_hid_semaphore);
+#endif
 
     /* Return the function status.  */
     return(status);
-#endif
 }
 
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