From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laurent Pinchart Subject: Re: [PATCH] Bugfixes for i2c-cpm.c Date: Wed, 2 Jul 2008 13:40:23 +0200 Message-ID: <200807021340.26926.laurentp@cse-semaphore.com> References: <20080620084155.GA17701@pengutronix.de> <4864A342.4020900@scram.de> <200807011526.14514.laurentp@cse-semaphore.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4657196607570836131==" Return-path: In-Reply-To: <200807011526.14514.laurentp-BSmb2szPELAwsLKNixborgC/G2K4zDHf@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: i2c-bounces-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Errors-To: i2c-bounces-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org To: i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --===============4657196607570836131== Content-Type: multipart/signed; boundary="nextPart5845269.3B3qxj3L67"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit --nextPart5845269.3B3qxj3L67 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Tuesday 01 July 2008, Laurent Pinchart wrote: > On Friday 27 June 2008, Jochen Friedrich wrote: > > Hi Laurent, > >=20 > > >> Bugfixes to the i2c-cpm driver > > >> > > >> - enable correct interrupts (I2CER_TXE instead of I2CER_BUSY) > > >> - replace forgotten iic with i2c > > >> - fix typo (devided) > > >> - prefix debug-output on init with 0x and add frequency > > >> > > >> Signed-off-by: Wolfram Sang > > >=20 > > > Tested on a MPC8247 board. I have experienced I2C issues since migrat= ion > > > from ppc to powerpc. This patch seems to solve the problem. > >=20 > > What kind of problems have this been? In normal operation there shouldn= 't > > be any I2CER_TXE interrupts being generated. >=20 > I2C devices would frequently (about once every 10 cold boots) be undetect= ed > by the kernel. I tried to investigate the issue by hooking up a scope to = the > I2C signals, but haven't been able to reproduce the problem once the prob= es > were connected. =20 >=20 > This might of course be a case of Murphy's law in action, but the problem > disappeared after applying the patch.=20 Seems Murphy's law was involved :-( I've run into the same issue just now. [ 0.555664] i2c /dev entries driver [ 0.564539] rtc-pcf8563 0-0051: chip found, driver version 0.4.3 [ 0.570038] rtc-pcf8563 0-0051: rtc core: registered rtc-pcf8563 as rtc0 [ 1.576209] i2c-adapter i2c-0: I2C transfer: timeout [ 1.579642] lm75: probe of 0-0048 failed with error -1 [snip] [ 2.766230] i2c-adapter i2c-0: I2C transfer: timeout [ 2.769602] rtc-pcf8563 0-0051: pcf8563_get_datetime: read error [ 2.775345] rtc-pcf8563 0-0051: hctosys: unable to read the hardware clo= ck =20 The lm75 is there and works after a reboot. In this particular run the pcf8= 563 was detected, but it would sometimes time out during probe as well. =2D-=20 Laurent Pinchart CSE Semaphore Belgium Chaussee de Bruxelles, 732A B-1410 Waterloo Belgium T +32 (2) 387 42 59 =46 +32 (2) 387 42 75 --nextPart5845269.3B3qxj3L67 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEABECAAYFAkhraSoACgkQ8y9gWxC9vpdr8wCgzUSbk4F5SDTUMQ2iTvzshMyT QisAnj/3dlq6mYmvjUXRks1zR2mZ+sz7 =OaCc -----END PGP SIGNATURE----- --nextPart5845269.3B3qxj3L67-- --===============4657196607570836131== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ i2c mailing list i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org http://lists.lm-sensors.org/mailman/listinfo/i2c --===============4657196607570836131==--