From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH 1/4] i2c: imx: check busy bit when START/STOP Date: Fri, 2 Oct 2009 16:11:06 +0200 Message-ID: <20091002141106.GG3179@pengutronix.de> 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> <4e090d470910011757g261c693ehdca40ce43ebee2ec@mail.gmail.com> <20091002072643.GH27039@pengutronix.de> <4e090d470910020117w620fda4cta7b26b912d01bc24@mail.gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="BzCohdixPhurzSK4" Return-path: Content-Disposition: inline In-Reply-To: <4e090d470910020117w620fda4cta7b26b912d01bc24-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Richard Zhao Cc: Sascha Hauer , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --BzCohdixPhurzSK4 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 02, 2009 at 04:17:09PM +0800, Richard Zhao wrote: > On Fri, Oct 2, 2009 at 3:26 PM, Sascha Hauer wro= te: > > On Fri, Oct 02, 2009 at 08:57:04AM +0800, Richard Zhao wrote: > >> On Fri, Oct 2, 2009 at 12:37 AM, Wolfram Sang = wrote: > >> >> > 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? > > > > Please remember that we do not have i.MX51 support in mainline, so this > > is irrelevant atm. > So I don't need to meantion mx51? "Without this patch, i2c on some > fast SoCs will not work" is all right? Sounds good to me! > > At the moment we have a driver which is not multi master capable. > > Looking at the datasheet the change you do seems not enough to change > > this. So we should take a patch which changes something from which you > > think it might be needed? And you don't even have the details at hand? > > > > No. > Ok, It seems I have no reason to keep the busy wait before START. > Wolfram, do you agree to remove the busy wait? If somebody really needs multi-master and is able to test it, then it can be reimplemented (but as said, this needs a lot more changes). Have to have a closer look though, if it may detect a stalled bus. > I saw you submmited the original driver. I helped in getting it accepted, but the commit is mainly from Darius. Regards, Wolfram --=20 Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | --BzCohdixPhurzSK4 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkrGCfoACgkQD27XaX1/VRtdtQCfQY/HExUvAyQbilCV+F83UZZ4 /ZQAnicn78e46mlqE3Z/9xXFMW8B2QCA =qYV9 -----END PGP SIGNATURE----- --BzCohdixPhurzSK4--