Re: [Discussion] USB: musb-gadget: how to fix ZLP issue in musb_g_tx

From: Sergei Shtylyov
Date: Wed Sep 15 2010 - 09:11:12 EST


Hello.

Felipe Balbi wrote:

On Wed, Sep 15, 2010 at 06:02:22AM -0500, Ming Lei wrote:
If so, once the dma interrupt comes, will request->actual be same
with request->length in musb_g_tx? And if it is true, could we remove the
check for 'is_dma'?

see that is_dma is set to true by just checking if dma in enabled in
txcsr, it might be that dma didn't complete everything and you need to
write txpktrdy by hand to send last short packet. So to remove that you
would need to re-work a bit more code.

I don't see what to rework. The last short packet should still satisfy (request->actual == request->length) condition, no?

You need to know when this is a dma IRQ or an endpoint IRQ.

We know that -- but why check it there, before (request->actual == request->length)?

WBR, Sergei
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