Re: [RESEND/PATCH 5/6] USB: musb-gadget: complete request only ifdata is transfered over
From: Sergei Shtylyov
Date: Wed Sep 15 2010 - 09:03:37 EST
Felipe Balbi wrote:
your forgetting the fact that not always you need to send ZLP after
completing a packet_size-aligned transfer,
So what?
what you're saying is that when we change the ZLP handling, the
request->actual == request->lenght check will have to be removed, but
that's not true because ZLP is only needed if request->zero is set.
So the final code would be something like (pseudo-code):
if (request->lenght % musb_ep->packet_sz)
set_last_packet_is_short_flag(musb_request);
if (request->zero || last_packet_is_short(request)) {
set_txpktrdy(musb);
set_musb_request_completed_flag(musb_request);
return;
}
if (request->acual == request->length)
musb_g_giveback(musb, request);
restart_ep_if_more_requests(musb_ep);
No, this code will still send ZLP before the whole requested transfer is
done. The (request->actual == request->length) check is needed before we even
check that request->zero is set (and it is there but not for the DMA case). I
thought that this was quite obvious, and I was surprised that this caused such a
lengthy discussion.
WBR, Sergei
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