Merge pull request #159 from hathach/retry-host-transaction

retry transaction up to 3 times for usb host

Author: sekigon-gonnoc

src/pio_usb.c

@@ -511,6 +511,7 @@ bool __no_inline_not_in_flash_func(pio_usb_ll_transfer_start)(endpoint_t *ep,
   ep->app_buf = buffer;
   ep->total_len = buflen;
   ep->actual_len = 0;
+  ep->failed_count = 0;
 
   if (ep->is_tx) {
     prepare_tx_data(ep);

src/pio_usb_host.c

@@ -21,6 +21,10 @@
 #include "usb_rx.pio.h"
 #include "usb_tx.pio.h"
 
+enum {
+  TRANSACTION_MAX_RETRY = 3, // Number of times to retry a failed transaction
+};
+
 static alarm_pool_t *_alarm_pool = NULL;
 static repeating_timer_t sof_rt;
 // The sof_count may be incremented and then read on different cores.
@@ -535,7 +539,14 @@ static int __no_inline_not_in_flash_func(usb_in_transaction)(pio_port_t *pp,
     if ((pp->pio_usb_rx->irq & IRQ_RX_COMP_MASK) == 0) {
       res = -2;
     }
-    pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_ERROR_BITS);
+
+    if (++ep->failed_count >= TRANSACTION_MAX_RETRY) {
+      pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_ERROR_BITS); // failed after 3 consecutive retries
+    }
+  }
+
+  if (res == 0) {
+    ep->failed_count = 0; // reset failed count if we got a sound response
   }
 
   pio_sm_set_enabled(pp->pio_usb_rx, pp->sm_rx, false);
@@ -569,7 +580,14 @@ static int __no_inline_not_in_flash_func(usb_out_transaction)(pio_port_t *pp,
   } else if (receive_token == USB_PID_STALL) {
     pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_STALLED_BITS);
   } else {
-    pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_ERROR_BITS);
+    res = -1;
+    if (++ep->failed_count >= TRANSACTION_MAX_RETRY) {
+      pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_ERROR_BITS);
+    }
+  }
+
+  if (res == 0) {
+    ep->failed_count = 0;// reset failed count if we got a sound response
   }
 
   pio_sm_set_enabled(pp->pio_usb_rx, pp->sm_rx, false);
@@ -581,7 +599,6 @@ static int __no_inline_not_in_flash_func(usb_out_transaction)(pio_port_t *pp,
 
 static int __no_inline_not_in_flash_func(usb_setup_transaction)(
     pio_port_t *pp,  endpoint_t *ep) {
-
   int res = 0;
 
   // Setup token
@@ -598,13 +615,19 @@ static int __no_inline_not_in_flash_func(usb_setup_transaction)(
   pio_usb_bus_wait_handshake(pp);
   pio_sm_set_enabled(pp->pio_usb_rx, pp->sm_rx, false);
 
-  ep->actual_len = 8;
-
   if (pp->usb_rx_buffer[0] == USB_SYNC && pp->usb_rx_buffer[1] == USB_PID_ACK) {
+    ep->actual_len = 8;
     pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_COMPLETE_BITS);
   } else {
     res = -1;
-    pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_ERROR_BITS);
+    ep->data_id = USB_PID_SETUP; // retry setup
+    if (++ep->failed_count >= TRANSACTION_MAX_RETRY) {
+      pio_usb_ll_transfer_complete(ep, PIO_USB_INTS_ENDPOINT_ERROR_BITS);
+    }
+  }
+
+  if (res == 0) {
+    ep->failed_count = 0;// reset failed count if we got a sound response
   }
 
   pp->usb_rx_buffer[1] = 0; // reset buffer

src/usb_definitions.h

@@ -75,6 +75,8 @@ typedef struct {
 
   uint8_t buffer[(64 + 4) * 2 * 7 / 6 + 2];
   uint8_t encoded_data_len;
+  uint8_t failed_count;
+
   uint8_t *app_buf;
   uint16_t total_len;
   uint16_t actual_len;