usbh: add enumeration control transfer timeoutclaude/usbh-enum-timeout

A device that ACKs SETUP but never completes the following stage (e.g. NAKs
the EP0 IN data stage forever) froze the control state machine: enumeration
never finishes and hub interrupt polling never resumes, so one dead device
blocks all further enumeration on the bus. Observed with a degraded USB disk
behind a hub on a rp2040 PIO-USB host: wire capture shows SETUP ACKed then
an endless IN/NAK storm with no completion event.

Arm a watchdog (CFG_TUH_ENUM_TIMEOUT_MS, default 5s to match Linux's
USB_CTRL_GET_TIMEOUT, 0 disables) on enumeration-owned control transfers
using the existing call_after slot, which already wakes a blocked host task.
On expiry abort the transfer at hcd level and complete it as FAILED so the
normal enumeration failure path frees dev0 and resumes hub polling.
Non-enumeration control transfers keep their current behavior.

1 files changed, 7 insertions, 0 deletions

diff --git a/src/tusb_option.h b/src/tusb_option.h
index 1eb23fb00..8b3a41a75 100644
--- a/src/tusb_option.h
+++ b/src/tusb_option.h
@@ -753,6 +753,13 @@
     #define CFG_TUH_ENUMERATION_BUFSIZE 256
   #endif
 
+  // Timeout in ms for each enumeration control transfer, 0 to wait forever.
+  // A broken device that ACKs SETUP but never completes the following stage would otherwise
+  // stall enumeration and hub polling forever. 5s matches Linux's USB_CTRL_GET_TIMEOUT.
+  #ifndef CFG_TUH_ENUM_TIMEOUT_MS
+    #define CFG_TUH_ENUM_TIMEOUT_MS 5000
+  #endif
+
 #endif // CFG_TUH_ENABLED
 
 // Attribute to place data in accessible RAM for host controller (default: CFG_TUSB_MEM_SECTION)