Hi,
On Tue, Sep 21, 2010 at 09:55:25AM -0500, Sergei Shtylyov wrote:
way the 'is_dma' check above that makes sense indeed...
heh.
Felipe, the revised patch will be sending out later to you...
Felipe, please drop this patch in favor of the previous implementation.
just being sure, this one:
commit fafbe39f0aefee04d888cbb6b9e969993d5f3dad
Author: Ming Lei <tom.leiming@xxxxxxxxx>
Date: Fri Sep 17 19:48:53 2010 -0500
USB: musb :gadget: fix ZLP handling in musb_g_tx
This patch fixes the problem reported by Sergei:
>how come? we need to send ZLP before giving back the request.
>Well, look at the code ionce again. We need to send ZLP *after*
>request->actual == request->length, but as the check is inserted
>after the ZLP send, ZLP *may* be sent once the first DMA completes,
>not the last.
The patch also has been discussed on the link below:
http://marc.info/?t=128454814900001&r=1&w=2
Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
Reported-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Anand Gadiyar <gadiyar@xxxxxx>
Cc: Mike Frysinger <vapier@xxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
diff --git a/drivers/usb/musb/musb_gadget.c b/drivers/usb/musb/musb_gadget.c
index e82c532..d3669b4 100644
--- a/drivers/usb/musb/musb_gadget.c
+++ b/drivers/usb/musb/musb_gadget.c
@@ -515,7 +515,13 @@ void musb_g_tx(struct musb *musb, u8 epnum)
epnum, csr, musb_ep->dma->actual_len, request);
}
- if (is_dma || request->actual == request->length) {
+ /*
+ * We should do the followings only if data transfer for
+ * the 'request' is over:
+ * - handle ZLP or short packet if meeting the conditions
+ * - complete the request
+ */
+ if (request->actual == request->length) {
/*
* First, maybe a terminating short packet. Some DMA
* engines might handle this by themselves.
@@ -541,14 +547,12 @@ void musb_g_tx(struct musb *musb, u8 epnum)
request->zero = 0;
}
- if (request->actual == request->length) {
- musb_g_giveback(musb_ep, request, 0);
- request = musb_ep->desc ? next_request(musb_ep) : NULL;
- if (!request) {
- DBG(4, "%s idle now\n",
- musb_ep->end_point.name);
- return;
- }
+ musb_g_giveback(musb_ep, request, 0);
+ request = musb_ep->desc ? next_request(musb_ep) : NULL;
+ if (!request) {
+ DBG(4, "%s idle now\n",
+ musb_ep->end_point.name);
+ return;
}
}
??
--
balbi
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