USB: s3c-hsotg: Only load packet per fifo write
Limit the IN FIFO write to a single packet per attempt at writing,
as per the specifications and ensure that we don't return fifo-full
so that we can continue writing packets if we have the space.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 4196e37..df6a39d 100644
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
@@ -538,6 +538,17 @@
if (can_write > 512)
can_write = 512;
+ /* limit the write to one max-packet size worth of data, but allow
+ * the transfer to return that it did not run out of fifo space
+ * doing it. */
+ if (to_write > hs_ep->ep.maxpacket) {
+ to_write = hs_ep->ep.maxpacket;
+
+ s3c_hsotg_en_gsint(hsotg,
+ periodic ? S3C_GINTSTS_PTxFEmp :
+ S3C_GINTSTS_NPTxFEmp);
+ }
+
/* see if we can write data */
if (to_write > can_write) {