usb: musb: gadget: fix ZLP sending in musb_g_tx(v1)

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@gmail.com>
Reported-by: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Anand Gadiyar <gadiyar@ti.com>
Cc: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Ming Lei 2010-09-24 13:44:14 +03:00 committed by Greg Kroah-Hartman
parent a6038ee76a
commit e7379aaa5c

View File

@ -477,40 +477,39 @@ void musb_g_tx(struct musb *musb, u8 epnum)
epnum, csr, musb_ep->dma->actual_len, request);
}
if (is_dma || request->actual == request->length) {
/*
* First, maybe a terminating short packet. Some DMA
* engines might handle this by themselves.
*/
if ((request->zero && request->length
&& request->length % musb_ep->packet_sz == 0)
/*
* First, maybe a terminating short packet. Some DMA
* engines might handle this by themselves.
*/
if ((request->zero && request->length
&& (request->length % musb_ep->packet_sz == 0)
&& (request->actual == request->length))
#ifdef CONFIG_USB_INVENTRA_DMA
|| (is_dma && (!dma->desired_mode ||
(request->actual &
(musb_ep->packet_sz - 1))))
|| (is_dma && (!dma->desired_mode ||
(request->actual &
(musb_ep->packet_sz - 1))))
#endif
) {
/*
* On DMA completion, FIFO may not be
* available yet...
*/
if (csr & MUSB_TXCSR_TXPKTRDY)
return;
) {
/*
* On DMA completion, FIFO may not be
* available yet...
*/
if (csr & MUSB_TXCSR_TXPKTRDY)
return;
DBG(4, "sending zero pkt\n");
musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
| MUSB_TXCSR_TXPKTRDY);
request->zero = 0;
}
DBG(4, "sending zero pkt\n");
musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
| MUSB_TXCSR_TXPKTRDY);
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;
}
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;
}
}