hack: force/overwrite endpoint mps to 64 for device that incorrectly report 512 bytes for bulk in fullspeed mode.

Author: hathach

src/class/midi/midi_host.c

@@ -267,10 +267,10 @@ bool midih_open(uint8_t rhport, uint8_t dev_addr, tusb_desc_interface_t const *d
         break;
 
       case TUSB_DESC_ENDPOINT: {
-        tusb_desc_endpoint_t const *p_ep = (tusb_desc_endpoint_t const *) p_desc;
+        const tusb_desc_endpoint_t *p_ep = (const tusb_desc_endpoint_t *) p_desc;
         p_desc = tu_desc_next(p_desc); // next to CS endpoint
         TU_VERIFY(p_desc < p_end && tu_desc_next(p_desc) <= p_end);
-        midi_desc_cs_endpoint_t const *p_csep = (midi_desc_cs_endpoint_t const *) p_desc;
+        const midi_desc_cs_endpoint_t *p_csep = (const midi_desc_cs_endpoint_t *) p_desc;
 
         TU_LOG_DRV("  Endpoint and CS_Endpoint descriptor %02x\r\n", p_ep->bEndpointAddress);
         if (tu_edpt_dir(p_ep->bEndpointAddress) == TUSB_DIR_OUT) {

src/common/tusb_private.h

@@ -67,7 +67,7 @@ typedef struct {
 //--------------------------------------------------------------------+
 
 // Check if endpoint descriptor is valid per USB specs
-bool tu_edpt_validate(tusb_desc_endpoint_t const * desc_ep, tusb_speed_t speed);
+bool tu_edpt_validate(tusb_desc_endpoint_t const * desc_ep, tusb_speed_t speed, bool is_host);
 
 // Bind all endpoint of a interface descriptor to class driver
 void tu_edpt_bind_driver(uint8_t ep2drv[][2], tusb_desc_interface_t const* p_desc, uint16_t desc_len, uint8_t driver_id);

src/device/usbd.c

@@ -1296,7 +1296,7 @@ bool usbd_edpt_open(uint8_t rhport, tusb_desc_endpoint_t const* desc_ep) {
   rhport = _usbd_rhport;
 
   TU_ASSERT(tu_edpt_number(desc_ep->bEndpointAddress) < CFG_TUD_ENDPPOINT_MAX);
-  TU_ASSERT(tu_edpt_validate(desc_ep, (tusb_speed_t) _usbd_dev.speed));
+  TU_ASSERT(tu_edpt_validate(desc_ep, (tusb_speed_t) _usbd_dev.speed, false));
 
   return dcd_edpt_open(rhport, desc_ep);
 }
@@ -1497,7 +1497,7 @@ bool usbd_edpt_iso_activate(uint8_t rhport, tusb_desc_endpoint_t const* desc_ep)
   uint8_t const dir = tu_edpt_dir(desc_ep->bEndpointAddress);
 
   TU_ASSERT(epnum < CFG_TUD_ENDPPOINT_MAX);
-  TU_ASSERT(tu_edpt_validate(desc_ep, (tusb_speed_t) _usbd_dev.speed));
+  TU_ASSERT(tu_edpt_validate(desc_ep, (tusb_speed_t) _usbd_dev.speed, false));
 
   _usbd_dev.ep_status[epnum][dir].stalled = 0;
   _usbd_dev.ep_status[epnum][dir].busy = 0;

src/host/usbh.c

@@ -986,7 +986,7 @@ static bool usbh_edpt_control_open(uint8_t dev_addr, uint8_t max_packet_size) {
 }
 
 bool tuh_edpt_open(uint8_t dev_addr, tusb_desc_endpoint_t const* desc_ep) {
-  TU_ASSERT(tu_edpt_validate(desc_ep, tuh_speed_get(dev_addr)));
+  TU_ASSERT(tu_edpt_validate(desc_ep, tuh_speed_get(dev_addr), true));
   return hcd_edpt_open(usbh_get_rhport(dev_addr), dev_addr, desc_ep);
 }
 

src/tusb.c

@@ -205,7 +205,7 @@ bool tu_edpt_release(tu_edpt_state_t* ep_state, osal_mutex_t mutex) {
   return ret;
 }
 
-bool tu_edpt_validate(tusb_desc_endpoint_t const* desc_ep, tusb_speed_t speed) {
+bool tu_edpt_validate(tusb_desc_endpoint_t const* desc_ep, tusb_speed_t speed, bool is_host) {
   uint16_t const max_packet_size = tu_edpt_packet_size(desc_ep);
   TU_LOG2("  Open EP %02X with Size = %u\r\n", desc_ep->bEndpointAddress, max_packet_size);
 
@@ -221,8 +221,17 @@ bool tu_edpt_validate(tusb_desc_endpoint_t const* desc_ep, tusb_speed_t speed) {
         // Bulk highspeed must be EXACTLY 512
         TU_ASSERT(max_packet_size == 512);
       } else {
-        // TODO Bulk fullspeed can only be 8, 16, 32, 64
-        TU_ASSERT(max_packet_size <= 64);
+        // Bulk fullspeed can only be 8, 16, 32, 64
+        if (is_host && max_packet_size == 512) {
+          // HACK: while in host mode, some device incorrectly always report 512 regardless of link speed
+          // overwrite descriptor to force 64
+          TU_LOG1("  WARN: EP max packet size is 512 in fullspeed, force to 64\r\n");
+          tusb_desc_endpoint_t* hacked_ep = (tusb_desc_endpoint_t*) (uintptr_t) desc_ep;
+          hacked_ep->wMaxPacketSize = tu_htole16(64);
+        } else {
+          TU_ASSERT(max_packet_size == 8  || max_packet_size == 16 ||
+                    max_packet_size == 32 || max_packet_size == 64);
+        }
       }
       break;