From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <52E110EC.4090009@geral.com> Date: Thu, 23 Jan 2014 13:54:04 +0100 From: Alexandre COFFIGNAL MIME-Version: 1.0 References: <52DF9C5F.70005@geral.com> <52DFAA18.6080703@xenomai.org> <52DFAD29.4000800@geral.com> <52DFB2DE.4050501@xenomai.org> <52DFC734.2090906@geral.com> <52DFC80D.6050101@xenomai.org> <52DFCFDE.9060700@geral.com> <52DFD1B0.6070303@xenomai.org> <52E0E93C.8010209@xenomai.org> <1bab8396d7c946110418979cb8177d9b@grandegger.com> In-Reply-To: <1bab8396d7c946110418979cb8177d9b@grandegger.com> Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Subject: Re: [Xenomai] imx28 rtcan flexcan system freezes List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: xenomai@xenomai.org Le 23/01/2014 12:36, Wolfgang Grandegger a écrit : > Hi Gilles, > > > > On Thu, 23 Jan 2014 11:04:44 +0100, Gilles Chanteperdrix > > wrote: > >> On 01/22/2014 03:12 PM, Gilles Chanteperdrix wrote: >>> On 01/22/2014 03:04 PM, Alexandre COFFIGNAL wrote: >>>> Le 22/01/2014 14:30, Gilles Chanteperdrix a écrit : >>>>> On 01/22/2014 02:27 PM, Alexandre COFFIGNAL wrote: >>>>>> Le 22/01/2014 13:00, Gilles Chanteperdrix a écrit : >>>>>>> On 01/22/2014 12:36 PM, Alexandre COFFIGNAL wrote: >>>>>>>>>> + cf->data[3]=((data0 >> 0) & 0xFF) ; >>>>>>>>>> + cf->data[2]=((data0 >> 8) & 0xFF) ; >>>>>>>>>> + cf->data[1]=((data0 >> 16) & 0xFF) ; >>>>>>>>>> + cf->data[0]=((data0 >> 24) & 0xFF) ; >>>>>>>>>> + cf->data[7]=((data1 >> 0) & 0xFF) ; >>>>>>>>>> + cf->data[6]=((data1 >> 8) & 0xFF) ; >>>>>>>>>> + cf->data[5]=((data1 >> 16) & 0xFF) ; >>>>>>>>>> + cf->data[4]=((data1 >> 24) & 0xFF) ; >>>>>>>>>> rtcan flexcan works perfectly. >>>>>>>>>> is anyone know what is the problem with first instructions ? >>>>>>>>> Probably mb->data does not have the right alignment. Could you > not > >>>>>>>>> arrange to get it properly aligned? Failing that, you should use >>>>>>>>> put_unaligned instead of open coding it. > > > How are unaligned accesses handled on your system? Alexandre, > > what does "cat /proc/cpu/alignment" report? Aligned access > > would be better, I agree. > > > >>>>>>>> here structures used in flexcan driver, it seem to be aligned >>>>>>> I am talking about the alignment of cf->data, since obviously, that >>>>>>> is >>>>>>> the one which is causing problems. >>>>>> Thank a lot, put_unaligned fix this issue if you want, i can send a >>>>>> path >>>>> The other solution (getting cf->data to be properly aligned) would be >>>>> more efficient, why is not it possible to get cf->data properly >>>>> aligned? >>>> I think, i can't get cf->data to be properly aligned because "cf" is >>>> receive internal frame representation within the ring buffer >>>> of a struct rtcan_socket and struct rtcan_rb_frame is a generic >>>> structure used in all rtcan drivers . >>> Well, if you fix rtcan_rb_frame to be aligned, it will be aligned for >>> all drivers, so that looks like a worthwile improvement... >> Wolfgang, what do you think? Should we change the alignment of >> rtcan_rb_frame::data, or use put_unaligned on ARM? > > > I realized the mail and wonder why this problem does not show up with > > vanilla > > Linux. Maybe we need to port over some patch from there. I will have a > > closer > > look this even or over the weekend. > > > > Wolfgang. > > > > _______________________________________________ > Xenomai mailing list > Xenomai@xenomai.org > http://www.xenomai.org/mailman/listinfo/xenomai Hi, "cat /proc/cpu/alignment" report User: 0 System: 0 Skipped: 0 Half: 0 Word: 0 DWord: 0 Multi: 0 User faults: 0 (ignored) something wrong with that ? Alexandre.