Hello.
On 23-03-2012 15:48, Lukasz Majewski wrote:
When sent data lenght is a multiple size of maximum packet size (MPS
= 64B for EP0), then sent a ZLP pbacket to indicate end of the
transfer to a USB host.
The above condition only applies, when requested data from host is NOT
equal to multiplied value of MPS (e.g. host requested 4096B from device).
I couldn't parse that. Of course 4096 is dividisble by 64. Adn you seem to
be contradiction the first paragraph.
In this case no ZLP shall be sent.
Tested with:
- DFU gadget (various size of the sent data - also packet = MPS)
- Ethernet gadget (CDC and RNDIS)
- Multi Function Gadget (g_multi)
HW:
- Samsung's C210 Universal rev.0
Signed-off-by: Lukasz Majewski<l.majewski@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park<kyungmin.park@xxxxxxxxxxx>
---
drivers/usb/gadget/s3c-hsotg.c | 34 ++++++++++++++++++++++++++++++++--
1 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
index 6ed259e..d67cb94 100644
--- a/drivers/usb/gadget/s3c-hsotg.c
+++ b/drivers/usb/gadget/s3c-hsotg.c
[...]
@@ -1831,9 +1842,28 @@ static void s3c_hsotg_complete_in(struct s3c_hsotg *hsotg,
__func__, hs_req->req.actual, size_done);
hs_req->req.actual = size_done;
+ dev_dbg(hsotg->dev, "req->length:%d req->actual:%d req->zero:%d\n",
+ hs_req->req.length, hs_req->req.actual, hs_req->req.zero);
+
+ /*
+ * Check if dealing with Maximum Packet Size(MPS) IN transfer at EP0
+ * When sent data is a multiple MPS size (e.g. 64B ,128B ,192B
+ * ,256B ... ), after last MPS sized packet send IN ZLP packet to
+ * inform the host that no more data is available.
+ * The state of req.zero member is checked to be sure that the value to
+ * send is smaller than wValue expected from host.
+ * Check req.length to NOT send another ZLP when the current one is
+ * under completion (the one for which this completion has been called).
+ */
+ if (hs_req->req.length && hs_ep->index == 0 && hs_req->req.zero
+ && hs_req->req.length == hs_req->req.actual
+ && !(hs_req->req.length % hs_ep->ep.maxpacket)) {
Ususally the operator is left on the prevsious line...
WBR, Sergei
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