From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Zhao Subject: Re: [PATCH 1/4] i2c: imx: check busy bit when START/STOP Date: Fri, 2 Oct 2009 08:57:04 +0800 Message-ID: <4e090d470910011757g261c693ehdca40ce43ebee2ec@mail.gmail.com> References: <1254359613-21210-1-git-send-email-linuxzsc@gmail.com> <4e090d470910010103o611d9fb2t3acf93632216fc88@mail.gmail.com> <20091001083831.GD27039@pengutronix.de> <4e090d470910010211k4ce78763i1a5163ec6ea57fe8@mail.gmail.com> <20091001095239.GE27039@pengutronix.de> <4e090d470910010754r1ebc4455u6220ccfd803491b0@mail.gmail.com> <20091001163753.GA20103@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20091001163753.GA20103-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang Cc: Sascha Hauer , kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-i2c@vger.kernel.org On Fri, Oct 2, 2009 at 12:37 AM, Wolfram Sang w= rote: >> > Ah, so 'make the driver work on i.MX51' is a good statement which = should >> > be part of the commit message. >> Well, maybe I can mention it. >> But I think the good point is to present what you modified, not the = side effect. > > It is not the side effect but the intention :) As no code is changed = without a > need, the reason really should be in the patch description. No, it's not intention. I'm just trying to make the controller work in a right way. Without this patch, maybe some other fast cpus have problem too. I just tested mx31 and mx51. I will add "Without this patch, i2c on some fast SoCs (for example imx51) will not work". Is it ok for you? > >> Yes. But I don't have multi-master system. So I can't say that. >> The code is just taken from Freescale latest code. Without it, It >> could also cause a device error. I forget the details. =A0Anyway, it >> doesn't make anything wrong. > > Do you know where the details are explained? No, I don't. I don't have device in hand now. If you have, could you please help do a simple test? Use hw to simulate multi-master system. Before execute xfer, you first pull down SDA, then pull down SDC. It simulates a START. and execute xfer to see whether IBB is set? Thanks Richard > > Regards, > > =A0 Wolfram > > -- > Pengutronix e.K. =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 = | Wolfram Sang =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0| > Industrial Linux Solutions =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 | http://w= ww.pengutronix.de/ =A0| > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.9 (GNU/Linux) > > iEYEARECAAYFAkrE2uEACgkQD27XaX1/VRumZQCeL4x9oaBKKjSKzJLlRrkfvvqg > nlEAoLpQdpI3TeKEvK13rs46kSZRDsZU > =3D7kM6 > -----END PGP SIGNATURE----- > >