From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: PCA9564: "bus is not idle" issue Date: Tue, 6 Apr 2010 09:52:08 +0200 Message-ID: <20100406075208.GA5102@pengutronix.de> References: <20100403162939.GA2190@pengutronix.de> <20100403202329.3bdb407c@hyperion.delvare> <20100404032929.GA12800@pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="6TrnltStXW4iwmi0" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yegor Yefremov Cc: Jean Delvare , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --6TrnltStXW4iwmi0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Apr 06, 2010 at 09:48:49AM +0200, Yegor Yefremov wrote: > >>> > > I'm using PCA9564 attached to a ks8695 SoC. During my efforts to = get > >>> > > 2.6.33/34 running on my system I noticed sporadic problems with R= TC: > >>> > > >>> > [...] > >>> > > >>> > > static struct i2c_pca9564_pf_platform_data =A0__initdata pca_data= =3D{ > >>> > > =A0 =A0 =A0 .gpio =3D -1, > >>> > > =A0 =A0 =A0 .i2c_clock_speed =3D 59000, > >>> > > =A0 =A0 =A0 .timeout =3D 1, > >>> > > }; > >>> > > >>> > Commit 8e99ada8deaa9033600cd2c7d0a9366b0e99ab68 changed the timeout= settings to > >>> > jiffies. So, one jiffy as timeout will not work. Try 'HZ' here. > >>> > >>> So this means the bug isn't in the mainline kernel tree and I can > >>> ignore it? > >> > >> A confirmation from Yegor would be nice, but his logs let me believe t= hat > >> this is really the cause. > >> > >>> As a side note, arch/blackfin/mach-bf561/boards/acvilon.c sets timeout > >>> to 10000, so the actual timeout depends on the value of HZ, which is > >>> probably not desirable. Not to mention that a timeout of over one > >>> minute (worst case) doesn't seem too smart ;) > >> > >> There is also an i2c-gpio-user using non-HZ value. Will prepare patche= s. > > > > Thank for your solution. I'll try it on Tuesday and confirm ASAP. >=20 > Wolfram, do you mean so: >=20 > static struct i2c_pca9564_pf_platform_data __initdata pca_data =3D{ > .gpio =3D -1, > .i2c_clock_speed =3D 59000, > .timeout =3D HZ, > }; >=20 > I've tried this, but with the same result. The bus is still not idle. That's bad news :(( Did you notice a difference in behaviour? There should = be a 1 second delay now before the message arises... --=20 Pengutronix e.K. | Wolfram Sang | Industrial Linux Solutions | http://www.pengutronix.de/ | --6TrnltStXW4iwmi0 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) iEYEARECAAYFAku66CgACgkQD27XaX1/VRvdQACffdmbB08StvrgD/Ww65UEB1Wn /wwAn1I9or+Lpjlha/4rFoFr3qKRkDbt =OFiD -----END PGP SIGNATURE----- --6TrnltStXW4iwmi0--