Commit 680cc645 authored by Daniel Glöckner's avatar Daniel Glöckner Committed by Greg Kroah-Hartman

USB: gadget: imx_udc: don't queue more data when zlp is to be sent

When a zero-length packet has been requested and another packet is
written into the fifo, the MX1 tends to send the first byte of the
previous packet instead of the first byte of the current packet.
The CRC is adjusted accordingly so that this packet is _not_
discarded by the host.

Waiting for the ZLPS bit to clear avoids these bad packets.
Signed-off-by: default avatarDaniel Glöckner <dg@emlix.com>
Cc: Darius Augulis <augulis.darius@gmail.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 2e251341
...@@ -415,6 +415,13 @@ static int write_packet(struct imx_ep_struct *imx_ep, struct imx_request *req) ...@@ -415,6 +415,13 @@ static int write_packet(struct imx_ep_struct *imx_ep, struct imx_request *req)
u8 *buf; u8 *buf;
int length, count, temp; int length, count, temp;
if (unlikely(__raw_readl(imx_ep->imx_usb->base +
USB_EP_STAT(EP_NO(imx_ep))) & EPSTAT_ZLPS)) {
D_TRX(imx_ep->imx_usb->dev, "<%s> zlp still queued in EP %s\n",
__func__, imx_ep->ep.name);
return -1;
}
buf = req->req.buf + req->req.actual; buf = req->req.buf + req->req.actual;
prefetch(buf); prefetch(buf);
......
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