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

Sergei Shtylyov
2010-09-15T13:11:07Z

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