io: Always complete transfers regardless of timerfd errors

This commit addresses two issues.

First, commit a886bb02 introduced an issue where transfer callbacks
would not be called if the transfer that completed was the first
in line and the timerfd needed to be armed for another transfer.

Second, failure to set the timerfd should not prevent the transfer
from completing. The behavior has always been such, but it will
leave clients waiting for their transfer callbacks to be called.
This change will let the transfer callback complete and will return
the error through the event handling path.

Signed-off-by: Chris Dickens <christopher.a.dickens@gmail.com>

diff --git a/libusb/io.c b/libusb/io.c
index 082441c..279288c 100644 (file)
--- a/libusb/io.c
+++ b/libusb/io.c
@@ -1316,8 +1316,7 @@ static int disarm_timerfd(struct libusb_context *ctx)
 /* iterates through the flying transfers, and rearms the timerfd based on the
  * next upcoming timeout.
  * must be called with flying_list locked.
- * returns 0 if there was no timeout to arm, 1 if the next timeout was armed,
- * or a LIBUSB_ERROR code on failure.
+ * returns 0 on success or a LIBUSB_ERROR code on failure.
  */
 static int arm_timerfd_for_next_timeout(struct libusb_context *ctx)
 {
@@ -1340,7 +1339,7 @@ static int arm_timerfd_for_next_timeout(struct libusb_context *ctx)
                        r = timerfd_settime(ctx->timerfd, TFD_TIMER_ABSTIME, &it, NULL);
                        if (r < 0)
                                return LIBUSB_ERROR_OTHER;
-                       return 1;
+                       return 0;
                }
        }
 
@@ -1426,8 +1425,8 @@ out:
 
 /* remove a transfer from the active transfers list.
  * This function will *always* remove the transfer from the
- * flying_transfers list. It will return non 0 if it fails to
- * update the timer for the next timeout. */
+ * flying_transfers list. It will return a LIBUSB_ERROR code
+ * if it fails to update the timer for the next timeout. */
 static int remove_from_flying_list(struct usbi_transfer *transfer)
 {
        struct libusb_context *ctx = ITRANSFER_CTX(transfer);
@@ -1624,8 +1623,8 @@ int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
        int r;
 
        r = remove_from_flying_list(itransfer);
-       if (r)
-               return r;
+       if (r < 0)
+               usbi_err(ITRANSFER_CTX(itransfer), "failed to set timer for next timeout, errno=%d", errno);
 
        usbi_mutex_lock(&itransfer->flags_lock);
        itransfer->flags &= ~USBI_TRANSFER_IN_FLIGHT;
@@ -1654,7 +1653,7 @@ int usbi_handle_transfer_completion(struct usbi_transfer *itransfer,
        if (flags & LIBUSB_TRANSFER_FREE_TRANSFER)
                libusb_free_transfer(transfer);
        libusb_unref_device(handle->dev);
-       return 0;
+       return r;
 }
 
 /* Similar to usbi_handle_transfer_completion() but exclusively for transfers

diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index f71f918..06f5699 100644 (file)
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 10999
+#define LIBUSB_NANO 11000