From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [MeeGo-Dev][PATCH v3] Topcliff: Update PCH_CAN driver to 2.6.35 Date: Tue, 05 Oct 2010 11:45:06 -0700 (PDT) Message-ID: <20101005.114506.184852374.davem@davemloft.net> References: <000401cb6477$25a0eba0$66f8800a@maildom.okisemi.com> <4CAB0732.3010400@pengutronix.de> <002e01cb6486$2ed72cc0$66f8800a@maildom.okisemi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: andrew.chih.howe.khor-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, sameo-VuQAYsv1563Yd54FQh9/CA@public.gmane.org, margie.foster-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org, yong.y.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org, mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, chripell-VaTbYqLCNhc@public.gmane.org, morinaga526-ECg8zkTtlr0C6LszWs/t0g@public.gmane.org, meego-dev-WXzIur8shnEAvxtiuMwx3w@public.gmane.org, kok.howg.ewe-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, joel.clark-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, qi.wang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org To: masa-korg-ECg8zkTtlr0C6LszWs/t0g@public.gmane.org Return-path: In-Reply-To: <002e01cb6486$2ed72cc0$66f8800a-a06+6cuVnkTSQfdrb5gaxUEOCMrvLtNR@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org Errors-To: socketcan-core-bounces-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org List-Id: netdev.vger.kernel.org From: "Masayuki Ohtake" Date: Tue, 5 Oct 2010 21:09:30 +0900 > On Tuesday, October 05, 2010 8:08 PM, Marc Kleine-Budde wrote: >> If FIFO is working you might also think about NAPI. > > I think NAPI isn't necessary for our CAN driver. > NAPI is for high-speed networking. > CAN is NOT high-speed. > > In fact, some accepted CAN drivers don't have NAPI. NAPI is not just for performance concerns. It greatly simplifies the locking since all packet processing paths run only in software interrupt context, never in hardware interrupt context. We encourage all new drivers that can use NAPI to do so, just because recent driver submissions do not do this doesn't mean we should continue such a mistake ;-)