From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elina Pasheva Subject: Re: [PATCH 1/1] NET: usb: Adding URB_ZERO_PACKET flag to usbnet.c Date: Wed, 7 Apr 2010 16:07:16 -0700 Message-ID: <1270681636.6401.5.camel@Linuxdev4-laptop> References: <1270599787.8900.8.camel@Linuxdev4-laptop> <201004071414.33917.david-b@pacbell.net> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Rory Filer , "netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , David Miller To: David Brownell Return-path: In-Reply-To: <201004071414.33917.david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: netdev.vger.kernel.org On Wed, 2010-04-07 at 14:14 -0700, David Brownell wrote: > On Tuesday 06 April 2010, you wrote: > Recall that the reason to avoid sending zero length packts > (ZLPs) is that many systems don't cope well with them... > > The ""don't cope well" can be at the hardware level, > or drivers not limited to device firmware. I've seen > the failures be very context-dependent .... as in, one > standalone ZLP might work, but mix it in with back-to-back > delivery of other packets and trouble ensues... > > In short, it's hard to know which combinations of > hardware an firmware would need it .... versus which > ones it would break. > > ... and thus risky to try sending ZLPs through systems > shere for many years) we've carefully avoided doing that. > > > - Dave > Hi Dave, Nice to hear your opinion on this matter. Are you recommending our patch be retracted? If so, we can look at other ways to fix the problem when a zero length packet is missing. Regards, Elina -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html