linux-kernel - Re: [Discussion] USB: musb-gadget: how to fix ZLP issue in musb_g

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <4C90C5B7.7050103@ru.mvista.com>
Date:	Wed, 15 Sep 2010 17:10:15 +0400
From:	Sergei Shtylyov <sshtylyov@...sta.com>
To:	balbi@...com
CC:	Ming Lei <tom.leiming@...il.com>,
	Sergei Shtylyov <sshtylyov@...sta.com>,
	"greg@...ah.com" <greg@...ah.com>,
	"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
	"linux-omap@...r.kernel.org" <linux-omap@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	David Brownell <dbrownell@...rs.sourceforge.net>,
	"Gadiyar, Anand" <gadiyar@...com>,
	Mike Frysinger <vapier@...too.org>
Subject: Re: [Discussion] USB: musb-gadget: how to fix ZLP issue in musb_g_tx

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/