Ursary: USB error recovery

diff --git a/ursaryd/nocturn.c b/ursaryd/nocturn.c
index 50d0557c9edff212fb797845822e66b052738647..12ea9c185ca83c5f343bda92001320344b28b137 100644 (file)
--- a/ursaryd/nocturn.c
+++ b/ursaryd/nocturn.c
@@ -14,6 +14,7 @@
 #include <ucw/clists.h>
 #include <ucw/gary.h>
 #include <ucw/mainloop.h>
+#include <ucw/stkstring.h>
 #include <ucw/string.h>
 
 #include <stdio.h>
@@ -27,6 +28,9 @@
 
 static libusb_context *usb_ctx;
 static libusb_device_handle *usb_dev;
+static bool usb_iface_claimed;
+
+static void noct_error(int usb_err, char *text);
 
 static struct main_file **usb_fds;
 
@@ -82,17 +86,18 @@ static const char noct_magic[4][9] = {
   { 2, 0x7f, 0x00 },
 };
 
+static struct libusb_transfer *noct_read_xfer;
+static bool noct_read_pending;
+
 static void noct_read_done(struct libusb_transfer *xfer)
 {
   byte *pkt = xfer->buffer;
   int len = xfer->actual_length;
   DBG("USB: Read done: status %d, length %d", xfer->status, len);
+  noct_read_pending = 0;
 
   if (xfer->status != LIBUSB_TRANSFER_COMPLETED)
-    {
-      msg(L_ERROR, "USB read failed with status %d, not submitting again", xfer->status);
-      return;
-    }
+    return noct_error(0, stk_printf("USB read failed with status %d", xfer->status));
 
 #ifdef LOCAL_DEBUG
   char buf[256];
@@ -191,19 +196,23 @@ static void noct_read_done(struct libusb_transfer *xfer)
 
   int err;
   if ((err = libusb_submit_transfer(xfer)) < 0)
-    die("Cannot submit transfer: error %d", err);
+    noct_error(err, "Cannot submit transfer");
+  else
+    noct_read_pending = 1;
 }
 
 static void noct_read_init(void)
 {
   DBG("Noct: Read init");
 
-  struct libusb_transfer *xfer = libusb_alloc_transfer(0);
-  libusb_fill_interrupt_transfer(xfer, usb_dev, 0x81, xmalloc(8), 8, noct_read_done, NULL, 0);
+  noct_read_xfer = libusb_alloc_transfer(0);
+  libusb_fill_interrupt_transfer(noct_read_xfer, usb_dev, 0x81, xmalloc(8), 8, noct_read_done, NULL, 0);
 
   int err;
-  if ((err = libusb_submit_transfer(xfer)) < 0)
-    die("Cannot submit transfer: error %d", err);
+  if ((err = libusb_submit_transfer(noct_read_xfer)) < 0)
+    noct_error(err, "Cannot submit transfer");
+  else
+    noct_read_pending = 1;
 }
 
 static byte noct_button_state[16];
@@ -215,7 +224,7 @@ static uns noct_dirty_ring_mode;
 static uns noct_dirty_ring_val;
 
 static struct libusb_transfer *noct_write_xfer;
-static uns noct_write_pending;
+static bool noct_write_pending;
 static void noct_sched_write(void);
 
 static void noct_write_done(struct libusb_transfer *xfer)
@@ -224,11 +233,7 @@ static void noct_write_done(struct libusb_transfer *xfer)
   DBG("USB: Write done: status %d, length %d", xfer->status, len);
 
   if (xfer->status != LIBUSB_TRANSFER_COMPLETED)
-    {
-      msg(L_ERROR, "USB write failed with status %d", xfer->status);
-      // FIXME: Handle the error in a meaningful way
-      return;
-    }
+    return noct_error(0, stk_printf("USB write failed with status %d", xfer->status));
   if (len < xfer->length)
     msg(L_ERROR, "USB partial write: %d out of %d", len, xfer->length);
 
@@ -250,7 +255,7 @@ static void noct_do_write(uns cmd, uns arg)
 
   int err;
   if ((err = libusb_submit_transfer(xfer)) < 0)
-    die("Cannot submit transfer: error %d", err);
+    noct_error(err, "Cannot submit transfer");
 }
 
 static void noct_sched_write(void)
@@ -333,6 +338,7 @@ static void noct_write_init(void)
 }
 
 static struct main_timer noct_connect_timer;
+static struct main_hook noct_error_hook;
 
 static void noct_connect(struct main_timer *t)
 {
@@ -372,22 +378,23 @@ static void noct_connect(struct main_timer *t)
   msg(L_DEBUG, "Initializing Nocturn");
 
   if ((err = libusb_open(found_dev, &usb_dev)) < 0)
-    die("libusb_open failed: error %d", err);
+    return noct_error(err, "libusb_open failed");
 
   // There exist configurations 1 (high brightness) and 2 (power-save)
   if ((err = libusb_set_configuration(usb_dev, 1)) < 0)
-    die("libusb_set_configuration: error %d", err);
+    return noct_error(err, "libusb_set_configuration failed");
 
   if ((err = libusb_claim_interface(usb_dev, 0)) < 0)
-    die("libusb_claim_interface: error %d", err);
+    return noct_error(err, "libusb_claim_interface failed");
+  usb_iface_claimed = 1;
 
   for (int i=0; i<4; i++)
     {
       int done;
       if ((err = libusb_interrupt_transfer(usb_dev, 0x02, (byte *) noct_magic[i] + 1, noct_magic[i][0], &done, 5000)) < 0)
-       die("Cannot send init packets: error %d", err);
+       return noct_error(err, "Cannot send init packets");
       if (done != noct_magic[i][0])
-       die("Partial send of init packet: %d < %d", done, noct_magic[i][0]);
+       return noct_error(err, stk_printf("Partial send of init packet (%d < %d)", done, noct_magic[i][0]));
     }
 
 #if 0
@@ -401,6 +408,66 @@ static void noct_connect(struct main_timer *t)
   schedule_update();
 }
 
+static int noct_error_handler(struct main_hook *h)
+{
+  DBG("Noct: Entered error handling hook");
+  hook_del(h);
+
+  if (usb_dev)
+    {
+      if (noct_read_xfer)
+       {
+         if (noct_read_pending)
+           {
+             DBG("Noct: Cancelling pending read");
+             libusb_cancel_transfer(noct_read_xfer);
+             noct_read_pending = 0;
+           }
+         DBG("Noct: Tearing down read xfer");
+         libusb_free_transfer(noct_read_xfer);
+         noct_read_xfer = NULL;
+       }
+      if (noct_write_xfer)
+       {
+         if (noct_write_pending)
+           {
+             DBG("Noct: Cancelling pending write");
+             libusb_cancel_transfer(noct_write_xfer);
+             noct_write_pending = 0;
+           }
+         DBG("Noct: Tearing down write xfer");
+         libusb_free_transfer(noct_write_xfer);
+         noct_write_xfer = NULL;
+       }
+      if (usb_iface_claimed)
+       {
+         DBG("Noct: Unclaiming interface");
+         libusb_release_interface(usb_dev, 0);
+         usb_iface_claimed = 0;
+       }
+      DBG("Noct: Resetting device");
+      libusb_reset_device(usb_dev);
+      libusb_close(usb_dev);
+      usb_dev = NULL;
+    }
+
+  DBG("Noct: Scheduling rescan after error");
+  timer_add_rel(&noct_connect_timer, 3000);
+
+  return HOOK_IDLE;
+}
+
+static void noct_error(int usb_err, char *text)
+{
+  if (usb_err)
+    msg(L_ERROR, "Nocturn: %s: error %d (%s)", text, usb_err, libusb_error_name(usb_err));
+  else
+    msg(L_ERROR, "Nocturn: %s", text);
+
+  DBG("Noct: Scheduling error handling hook");
+  hook_add(&noct_error_hook);
+}
+
 bool noct_is_ready(void)
 {
   return !!usb_dev;    // FIXME
@@ -429,6 +496,9 @@ void noct_init(void)
     usb_added_fd(fds[i]->fd, fds[i]->events, NULL);
   free(fds);
 
+  // Prepare error handling hook
+  noct_error_hook.handler = noct_error_handler;
+
   // Schedule search for the Nocturn
   noct_connect_timer.handler = noct_connect;
   timer_add_rel(&noct_connect_timer, 0);