HACK: Solve weird problem with lost OUT transfer on ping-pong endpoint
This adds an unconditional endpoint reset procedure to every SET_FEATURE(UnHalt).
It doesn't really make sense that this is required, *particularly* as
we *MUST NOT* set bEndpoint->bank to 0 here.
Without this patch, I'm observing the following problem:
Every first OUT transfer after a SET_INTERFACE + UNHALT on a bulk endpoint
is lost. "lost" means that it completes successfully on the host, can
be seen completing successfully with an ACK on a USB bus analyzer,
but still doesn't show up in the firmware. No Endpoint Interrupt
is generated.
This can be reproduced by calling libusb_set_interface_alt_setting()
from the host and then submitting a single OUT transfer.
Change-Id: I18ed530e617baddf76e8f9829512443ce2a76e0d
diff --git a/firmware/atmel_softpack_libraries/libchip_sam3s/source/USBD_HAL.c b/firmware/atmel_softpack_libraries/libchip_sam3s/source/USBD_HAL.c
index 1ebab5b..e6edda6 100644
--- a/firmware/atmel_softpack_libraries/libchip_sam3s/source/USBD_HAL.c
+++ b/firmware/atmel_softpack_libraries/libchip_sam3s/source/USBD_HAL.c
@@ -1672,6 +1672,10 @@
UDP->UDP_RST_EP |= 1 << bEndpoint;
UDP->UDP_RST_EP &= ~(1 << bEndpoint);
}
+
+ /* This fixes a weird bug with regard to ping-pong OUT endpoints */
+ UDP->UDP_RST_EP |= 1 << bEndpoint;
+ UDP->UDP_RST_EP &= ~(1 << bEndpoint);
}
/* Return Halt status */