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authorDaniel Glöckner <dg@emlix.com>2009-05-28 13:00:14 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2009-06-15 21:44:46 -0700
commit680cc64557101eaaca706dc9a1a0777f35aac0da (patch)
tree9127ca038b29340185caff4621126ae83baf14f1
parent2e25134122c25ebb0679b4bbd536fb46c669f9d7 (diff)
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: Daniel Glöckner <dg@emlix.com> Cc: Darius Augulis <augulis.darius@gmail.com> Cc: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/gadget/imx_udc.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/usb/gadget/imx_udc.c b/drivers/usb/gadget/imx_udc.c
index 239bf8ed9f4..c52a681f376 100644
--- a/drivers/usb/gadget/imx_udc.c
+++ b/drivers/usb/gadget/imx_udc.c
@@ -415,6 +415,13 @@ static int write_packet(struct imx_ep_struct *imx_ep, struct imx_request *req)
u8 *buf;
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;
prefetch(buf);