Re: [RESEND/PATCH 5/6] USB: musb-gadget: complete request only ifdata is transfered over

From: Felipe Balbi
Date: Tue Sep 14 2010 - 06:54:24 EST


Hi,

On Tue, Sep 14, 2010 at 05:46:22AM -0500, Sergei Shtylyov wrote:
If a DMA interrupt comes when the whole transfer is not yet complete (and
other Ming Lei's patches are making this possible), it will pass due to the

than this is the actual problem, no ? If we're using mode1 dma (as we
are on tx path), we should only get dma interrupt when the whole
transfer has been completed.

'ís_dma' condition above the patched code:

if (is_dma || request->actual == request->length) {

and then it will hit the code sending the final ZLP (above this patched code too):

but this was already there before the patch.

/*
* 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)
#ifdef CONFIG_USB_INVENTRA_DMA
|| (is_dma && (!dma->desired_mode ||
(request->actual &
(musb_ep->packet_sz - 1))))
#endif
) {

before the transfer is complete while it should only be hit when and only when
the whole transfer is complete. The current code doesn't look correct as well
though, all due to this 'ís_dma' condition. Surely this needs fixing.

likewise, this was there before the patch. I don't think the real
problem lies with this patch, it's been there for a while, don't you
agree ?

the problem is not on the extra if () added below the quoted code,
it's on the quoted code itself, which wasn't changed in any way.

--
balbi
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