Hello.
Holger brunck wrote:
From: Stefan Bigler <stefan.bigler@xxxxxxxxxxx>
Some usb serial host drivers expect a short packet before they forward
the data to the application. This is caused by them trying to read more
than one packet at a time. So when the gadget sends an exact multiple
of the maximum packet size, it should append a zero-length packet.
The gadget driver for fsl_qe was not handling this case correctly.
This patch adds sending of a null packet if it is the last packet of
a frame and the request length is USB_EP0_MAX_SIZE (64 Byte).
See also commit 2e25134122c25ebb0679b4bbd536fb46c669f9d7
Linus has asked to also specify
Signed-off-by: Stefan Bigler <stefan.bigler@xxxxxxxxxxx>
Signed-off-by: Holger Brunck <holger.brunck@xxxxxxxxxxx>
Cc: Li Yang <leoli@xxxxxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/fsl_qe_udc.c | 3 +++
1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c
index 7881f12..279454a 100644
--- a/drivers/usb/gadget/fsl_qe_udc.c
+++ b/drivers/usb/gadget/fsl_qe_udc.c
@@ -1229,6 +1229,9 @@ static int frame_create_tx(struct qe_ep *ep, struct qe_frame *frame)
else
reval = sendnulldata(ep, frame, 0);
No, really you shouldn't send null data in every case when req->req.length -
ep->sent <= 0, only if req->req.length == 0 or req->req.zero == 1...
+ if (req->req.zero && (req->req.length == USB_EP0_MAX_SIZE))
Not (req->req.length % USB_EP0_MAX_SIZE == 0)? Also, you should probably
check that ep->sent == req->req.length here...
+ reval = sendnulldata(ep, frame, 0);
+
return reval;
}
WBR, Sergei
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