diff options
| author | Keith Packard <keithp@keithp.com> | 2009-11-04 21:32:07 -0800 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2009-11-04 21:32:07 -0800 |
| commit | 3ece984f4d72b4f720a5efdfaad7cff77a93d676 (patch) | |
| tree | 9c351576c0e3f295461bc9a81867998dc38cc401 /src/ao_usb.c | |
| parent | bc62bb254085cc705203b57260c04ac5e14c6611 (diff) | |
In USB pollchar, wait for packet before re-checking USB out len
This probably wouldn't actually cause a problem, but it seems more
reliable to wait for a packet interrupt before re-reading the packet
OUT len register. This could avoid spinning while waiting for a USB
packet, which seems like a good thing.
Signed-off-by: Keith Packard <keithp@keithp.com>
Diffstat (limited to 'src/ao_usb.c')
| -rw-r--r-- | src/ao_usb.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/src/ao_usb.c b/src/ao_usb.c index daca71a7..527e9b30 100644 --- a/src/ao_usb.c +++ b/src/ao_usb.c @@ -377,11 +377,13 @@ char ao_usb_pollchar(void) __critical { char c; - while (ao_usb_out_bytes == 0) { + if (ao_usb_out_bytes == 0) { USBINDEX = AO_USB_OUT_EP; if ((USBCSOL & USBCSOL_OUTPKT_RDY) == 0) return AO_READ_AGAIN; ao_usb_out_bytes = (USBCNTH << 8) | USBCNTL; + if (ao_usb_out_bytes == 0) + return AO_READ_AGAIN; } --ao_usb_out_bytes; c = USBFIFO[AO_USB_OUT_EP << 1]; |