fix(hid): Store client instance per-device instead of per-class (#262)

* fix(hid): Store client instance per-device instead of per-class

* Address review feedback on per-instance HID client copy

Three issues fixed, discovered during maintainer review:

1. Memory leak in standalone activation error path (entry.c):
   _ux_host_class_hid_client_activate_wait() set hid_client to NULL
   without freeing the per-instance copy allocated in client_search.
   The HID_ENUM_ERROR handler destroys the hid struct without freeing
   hid_client, so the copy was leaked on every standalone activation
   failure. Fixed by freeing hid_client before clearing it.

2. Variable declared inside if-block (client_search.c):
   hid_client_instance was declared inside the if (status == UX_SUCCESS)
   block, which is a C99 feature. USBX targets C89/C90 embedded
   toolchains. Moved to the top of the function with other locals.

3. Trailing whitespace throughout both changed files:
   The PR introduced trailing spaces on most comment-block lines.
   Reverted all affected lines to their original whitespace.

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

---------

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

3 files changed, 34 insertions, 5 deletions

diff --git a/common/usbx_host_classes/src/ux_host_class_hid_client_search.c b/common/usbx_host_classes/src/ux_host_class_hid_client_search.c
index bf68885..902cd55 100644
--- a/common/usbx_host_classes/src/ux_host_class_hid_client_search.c
+++ b/common/usbx_host_classes/src/ux_host_class_hid_client_search.c
@@ -56,6 +56,9 @@
 /*  CALLS                                                                 */
 /*                                                                        */
 /*    (ux_host_class_hid_client_handler)    HID client handler            */
+/*    _ux_utility_memory_allocate           Allocate memory block         */
+/*    _ux_utility_memory_copy               Copy memory block             */
+/*    _ux_utility_memory_free               Release memory block          */
 /*                                                                        */
 /*  CALLED BY                                                             */
 /*                                                                        */
@@ -66,6 +69,7 @@ UINT  _ux_host_class_hid_client_search(UX_HOST_CLASS_HID *hid)
 {
 
 UX_HOST_CLASS_HID_CLIENT            *hid_client;
+UX_HOST_CLASS_HID_CLIENT            *hid_client_instance;
 ULONG                               hid_client_index;
 UINT                                status;
 UX_HOST_CLASS_HID_CLIENT_COMMAND    hid_client_command;
@@ -109,18 +113,36 @@ UX_HOST_CLASS_HID_CLIENT_COMMAND    hid_client_command;
             if (status == UX_SUCCESS)
             {
 
+                /* Allocate a per-instance copy of the client struct so that each HID
+                   device gets its own local_instance pointer. This prevents multiple
+                   devices of the same type from sharing a single local_instance.  */
+                hid_client_instance = (UX_HOST_CLASS_HID_CLIENT *)
+                    _ux_utility_memory_allocate(UX_NO_ALIGN, UX_REGULAR_MEMORY,
+                                                sizeof(UX_HOST_CLASS_HID_CLIENT));
+                if (hid_client_instance == UX_NULL)
+                    return(UX_MEMORY_INSUFFICIENT);
+
+                /* Copy the registered client entry and clear the local instance
+                   to avoid carrying a stale pointer from a prior activation.  */
+                _ux_utility_memory_copy(hid_client_instance, hid_client,
+                                        sizeof(UX_HOST_CLASS_HID_CLIENT));
+                hid_client_instance -> ux_host_class_hid_client_local_instance = UX_NULL;
+
                 /* Update the command to activate the client.  */
                 hid_client_command.ux_host_class_hid_client_command_request =  UX_HOST_CLASS_COMMAND_ACTIVATE;
 
-                /* Memorize the client for this HID device.  */
-                hid -> ux_host_class_hid_client =  hid_client;
+                /* Store the per-instance client on this HID device.  */
+                hid -> ux_host_class_hid_client =  hid_client_instance;
 
                 /* Call the HID client with an activate command.  */
-                status =  hid_client -> ux_host_class_hid_client_handler(&hid_client_command);
+                status =  hid_client_instance -> ux_host_class_hid_client_handler(&hid_client_command);
 
-                /* Unmount the client if activation fail. */
+                /* Unmount the client if activation failed. */
                 if (status != UX_SUCCESS)
+                {
                     hid -> ux_host_class_hid_client = UX_NULL;
+                    _ux_utility_memory_free(hid_client_instance);
+                }
 
                 /* Return completion status.  */
                 return(status);
diff --git a/common/usbx_host_classes/src/ux_host_class_hid_deactivate.c b/common/usbx_host_classes/src/ux_host_class_hid_deactivate.c
index eab333f..d3db9ac 100644
--- a/common/usbx_host_classes/src/ux_host_class_hid_deactivate.c
+++ b/common/usbx_host_classes/src/ux_host_class_hid_deactivate.c
@@ -138,11 +138,17 @@ UINT                                status;
     hid_client_command.ux_host_class_hid_client_command_instance =   (VOID *) hid;
     hid_client_command.ux_host_class_hid_client_command_container =  (VOID *) hid -> ux_host_class_hid_class;
     hid_client_command.ux_host_class_hid_client_command_request =    UX_HOST_CLASS_COMMAND_DEACTIVATE;
-
+    
     /* Call the HID client with a deactivate command if there was a client registered.  */
     if (hid -> ux_host_class_hid_client != UX_NULL)
+    {
         hid -> ux_host_class_hid_client -> ux_host_class_hid_client_handler(&hid_client_command);
 
+        /* Free the per-instance client copy allocated in _ux_host_class_hid_client_search.  */
+        _ux_utility_memory_free(hid -> ux_host_class_hid_client);
+        hid -> ux_host_class_hid_client = UX_NULL;
+    }
+
     /* Clean all the HID memory fields.  */
     _ux_host_class_hid_instance_clean(hid);
 
diff --git a/common/usbx_host_classes/src/ux_host_class_hid_entry.c b/common/usbx_host_classes/src/ux_host_class_hid_entry.c
index 0902432..9acc9d3 100644
--- a/common/usbx_host_classes/src/ux_host_class_hid_entry.c
+++ b/common/usbx_host_classes/src/ux_host_class_hid_entry.c
@@ -456,6 +456,7 @@ UINT                                status;
     /* Error.  */
     if (status < UX_STATE_NEXT)
     {
+        _ux_utility_memory_free(hid -> ux_host_class_hid_client);
         hid -> ux_host_class_hid_client = UX_NULL;
         hid -> ux_host_class_hid_status = UX_DEVICE_ENUMERATION_FAILURE;
         hid -> ux_host_class_hid_enum_state = UX_HOST_CLASS_HID_ENUM_ERROR;