From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: [MeeGo-Dev][PATCH] Topcliff: Update PCH_CAN driver to 2.6.35 Date: Fri, 13 Aug 2010 12:58:39 +0200 Message-ID: <4C65255F.4010709@grandegger.com> References: <4C61EDE5.4030505@dsn.okisemi.com> <4C63B8F8.6090106@grandegger.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: "Khor, Andrew Chih Howe" , Masayuki Ohtak , "netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "gregkh-l3A5Bk7waGM@public.gmane.org" , "Wang, Yong Y" , "socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org" , "meego-dev-WXzIur8shnEAvxtiuMwx3w@public.gmane.org" , "arjan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org" To: "Wang, Qi" Return-path: In-Reply-To: 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 On 08/13/2010 02:23 AM, Wang, Qi wrote: >> -----Original Message----- >> From: Wolfgang Grandegger [mailto:wg-5Yr1BZd7O62+XT7JhA+gdA@public.gmane.org] >> Sent: Thursday, August 12, 2010 5:04 PM >> To: Wang, Qi >> Cc: Daniel Baluta; Masayuki Ohtak; meego-dev-WXzIur8shnEAvxtiuMwx3w@public.gmane.org; >> socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org; netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Khor, Andrew Chih >> Howe; gregkh-l3A5Bk7waGM@public.gmane.org; arjan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org; Wang, Yong Y >> Subject: Re: [MeeGo-Dev][PATCH] Topcliff: Update PCH_CAN driver to 2.6.35 >> >> On 08/12/2010 03:42 AM, Wang, Qi wrote: >>>> -----Original Message----- >>>> From: Daniel Baluta [mailto:daniel.baluta-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org] >>>> Sent: Wednesday, August 11, 2010 6:37 PM >>>> To: Masayuki Ohtak >>>> Cc: meego-dev-WXzIur8shnEAvxtiuMwx3w@public.gmane.org; Wolfgang Grandegger; >>>> socketcan-core-0fE9KPoRgkgATYTw5x5z8w@public.gmane.org; netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Khor, Andrew >> Chih >>>> Howe; gregkh-l3A5Bk7waGM@public.gmane.org; arjan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org; Wang, Qi; Wang, Yong Y >>>> Subject: Re: [MeeGo-Dev][PATCH] Topcliff: Update PCH_CAN driver to 2.6.35 >>>> >>>> Hi, >>>> >>>> 2010/8/11 Masayuki Ohtak : >>>>> CAN driver of Topcliff PCH >>>>> >>>>> Topcliff PCH is the platform controller hub that is going to be used in >>>>> Intel's upcoming general embedded platform. All IO peripherals in >>>>> Topcliff PCH are actually devices sitting on AMBA bus. >>>>> Topcliff PCH has CAN I/F. This driver enables CAN function. >>>>> >>>>> Signed-off-by: Masayuki Ohtake >>>> >>>> I have a few questions: >>>> >>>> 1. Is your code based on Intel's CAN EP80579 ([1]) ? >>> No. >> >> For curiosity, is the controller similar to the OKI MSM9225 or ML9620? > The Topcliff IOH is developed by OKI actually. > >> >>>> 2. Why don't you use kernel existing kfifo infrastructure? ([2]). >>> Just take a look at kfifo.h. This structure has been changed. I remembered >> there was a spin_lock from kfifo previously. Currently it's been removed, good. >>> OKI-sans, would you please take a look at ./include/linux/kfifo.h, and try to >> use this structure and APIs? >> >> As I see it, the code related to that fifo is not used (== dead code)? > I'm not familiar with kfifo structure, and I didn't like it because there need a spin_lock to use it. >> >>> Daniel, >>> >>> We're anxious to integrate those codes now. Perhaps it'll take us quite a long >> time to use kfifo. How about implementing it with the next version? >> >> See above. What do you mean with the next version. The driver posted by >> Masayuki is far away from being accepted as it does not yet comply with >> the Socket-CAN driver API, to say the least. > I've few experience on CAN driver and it's also the first time for OKI-san to write Can driver. Would you please give us a reference and we'll follow it up. We only read 'can.txt' from kernel document. Thank you for your help in advance. You are welcome. I think I/we already gave useful hints on what is missing and what examples to follow. Wolfgang.