From mboxrd@z Thu Jan 1 00:00:00 1970 From: Craig Matsuura Subject: Re: [PATCH/RFC 1/1] recover from davinci i2c time out conditions Date: Mon, 21 Sep 2009 07:41:21 -0600 Message-ID: <200909210741.22154.cmatsuura@control4.com> References: <1247643267.5981.82.camel@localhost.localdomain> <200909182312.58018.cmatsuura@control4.com> <1253514660.4507.2.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0861376340==" Return-path: In-Reply-To: <1253514660.4507.2.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: davinci-linux-open-source-bounces-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org Errors-To: davinci-linux-open-source-bounces-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org To: Philby John Cc: khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org, davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-i2c@vger.kernel.org --===============0861376340== Content-Type: multipart/alternative; boundary="Boundary-00=_CK4tK/KgUw3jbhL" Content-Transfer-Encoding: 7bit Content-Disposition: inline --Boundary-00=_CK4tK/KgUw3jbhL Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Philby, Sorry, I forgot to mention, I did correct a problem with accessing a regs, it is where yo usend a NACK. I changed the read from DAVINCI_I2C_IMR_REG to DAVINCI_I2C_MDR_REG. + flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG); + flag |= DAVINCI_I2C_MDR_NACK; + /* write the data into mode register */ + davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag); Craig On Monday 21 September 2009 12:31:00 am Philby John wrote: > Hello Craig, > > Good to know. With out any modifications on a DM6443? > > Regards, > Philby > > On Fri, 2009-09-18 at 23:12 -0600, Craig Matsuura wrote: > > The patch submitted appears specific to the dm355. The changes are > > very similar to the 2.6.10 kernel from mv. If the correct gpio's and > > pinmux are disabled/enabled it should work for the dm644x. > > > > > > > > I took the patch from Philby and tried it on our dm6443 platform (on a > > 2.6.28 kernel) and it appears to work for the problem we have when the > > i2c appears to lock up. > > > > > > > > Craig > > > > On Wednesday 22 July 2009 5:14:35 am Philby John wrote: > > > On Wed, 2009-07-22 at 04:03 -0700, Nitin Mahajan wrote: > > > > Hello, > > > > > > > > ----- Original Message ---- > > > > > > > > > From: Philby John > > > > > To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > > > > > Cc: khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org; > > > > davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org > > > > > > > Sent: Wednesday, July 15, 2009 13:04:27 > > > > > Subject: [PATCH/RFC 1/1] recover from davinci i2c time out > > > > conditions > > > > > > > >From dbe7e824d576636bb15b82a20fd2557fddc9a8f7 Mon Sep 17 > > > > 00:00:00 2001 > > > > > > > From: Philby John > > > > > Date: Tue, 14 Jul 2009 21:46:47 +0530 > > > > > Subject: [PATCH] Reset i2c bus to come out of time out > > > > conditions > > > > > > > Get out of i2c time out condition by resetting > > > > > the i2c bus. The kernel must be robust enough to > > > > > gracefully recover from i2c bus failure without having > > > > > to reset the machine. This is done by first NACKing the slave > > > > > and then resetting the i2c bus after a certain timeout. > > > > > > > > > > Signed-off-by: Philby John > > > > > > > > I tried this on DM6443 based board with 2.6.18 kernel. The result > > > > I am > > > > > > posting below. It gives controller time out again and again. > > > > > > > > dhcppc9 login: i2c_davinci i2c_davinci.1: controller timed out > > > > i2c_davinci i2c_davinci.1: initiating i2c bus recovery > > > > i2c_davinci i2c_davinci.1: controller timed out > > > > i2c_davinci i2c_davinci.1: initiating i2c bus recovery > > > > > > There is something gravely wrong about this patch and I would submit > > > > a > > > > > fix shortly incorporating the review comments. But please be aware > > > > that > > > > > I do not guarantee a definitive time line for a fix cause I have > > > > much at > > > > > hand at the moment. > > > > > > > > > Regards, > > > Philby > > > > > > > > > _______________________________________________ > > > Davinci-linux-open-source mailing list > > > Davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org > > > > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source > > > > -- > > > > > > > > > > > > ______________________________________________________________________ > > > > > > Craig Matsuura - Principal Engineer > > Control4 > > 11734 South Election Road - Suite 200 > > Salt Lake City, UT 84020-6432 > > PH: 801-523-3161 > > FX: 801-523-3199 -- Craig Matsuura - Principal Engineer Control4 11734 South Election Road - Suite 200 Salt Lake City, UT 84020-6432 PH: 801-523-3161 FX: 801-523-3199 --Boundary-00=_CK4tK/KgUw3jbhL Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: 7bit Philby,


Sorry, I forgot to mention, I did correct a problem with accessing a regs, it is where yo usend a NACK. I changed the read from DAVINCI_I2C_IMR_REG to DAVINCI_I2C_MDR_REG.


+ flag = davinci_i2c_read_reg(dev, DAVINCI_I2C_IMR_REG);
+ flag |= DAVINCI_I2C_MDR_NACK;
+ /* write the data into mode register */
+ davinci_i2c_write_reg(dev, DAVINCI_I2C_MDR_REG, flag);



Craig


On Monday 21 September 2009 12:31:00 am Philby John wrote:
> Hello Craig,
>
> Good to know. With out any modifications on a DM6443?
>
> Regards,
> Philby
>
> On Fri, 2009-09-18 at 23:12 -0600, Craig Matsuura wrote:
> > The patch submitted appears specific to the dm355. The changes are
> > very similar to the 2.6.10 kernel from mv. If the correct gpio's and
> > pinmux are disabled/enabled it should work for the dm644x.
> >
> >
> >
> > I took the patch from Philby and tried it on our dm6443 platform (on a
> > 2.6.28 kernel) and it appears to work for the problem we have when the
> > i2c appears to lock up.
> >
> >
> >
> > Craig
> >
> > On Wednesday 22 July 2009 5:14:35 am Philby John wrote:
> > > On Wed, 2009-07-22 at 04:03 -0700, Nitin Mahajan wrote:
> > > > Hello,
> > > >
> > > > ----- Original Message ----
> > > >
> > > > > From: Philby John <pjohn-k0rHJ+Hhz/SB+jHODAdFcQ@public.gmane.org>
> > > > > To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
> > > > > Cc: khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org;
> >
> > davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org
> >
> > > > > Sent: Wednesday, July 15, 2009 13:04:27
> > > > > Subject: [PATCH/RFC 1/1] recover from davinci i2c time out
> >
> > conditions
> >
> > > > > >From dbe7e824d576636bb15b82a20fd2557fddc9a8f7 Mon Sep 17
> >
> > 00:00:00 2001
> >
> > > > > From: Philby John
> > > > > Date: Tue, 14 Jul 2009 21:46:47 +0530
> > > > > Subject: [PATCH] Reset i2c bus to come out of time out
> >
> > conditions
> >
> > > > > Get out of i2c time out condition by resetting
> > > > > the i2c bus. The kernel must be robust enough to
> > > > > gracefully recover from i2c bus failure without having
> > > > > to reset the machine. This is done by first NACKing the slave
> > > > > and then resetting the i2c bus after a certain timeout.
> > > > >
> > > > > Signed-off-by: Philby John
> > > >
> > > > I tried this on DM6443 based board with 2.6.18 kernel. The result
> >
> > I am
> >
> > > > posting below. It gives controller time out again and again.
> > > >
> > > > dhcppc9 login: i2c_davinci i2c_davinci.1: controller timed out
> > > > i2c_davinci i2c_davinci.1: initiating i2c bus recovery
> > > > i2c_davinci i2c_davinci.1: controller timed out
> > > > i2c_davinci i2c_davinci.1: initiating i2c bus recovery
> > >
> > > There is something gravely wrong about this patch and I would submit
> >
> > a
> >
> > > fix shortly incorporating the review comments. But please be aware
> >
> > that
> >
> > > I do not guarantee a definitive time line for a fix cause I have
> >
> > much at
> >
> > > hand at the moment.
> > >
> > >
> > > Regards,
> > > Philby
> > >
> > >
> > > _______________________________________________
> > > Davinci-linux-open-source mailing list
> > > Davinci-linux-open-source-VycZQUHpC/PFrsHnngEfi1aTQe2KTcn/@public.gmane.org
> >
> > http://linux.davincidsp.com/mailman/listinfo/davinci-linux-open-source
> >
> > --
> >
> >
> >
> >
> >
> > ______________________________________________________________________
> >
> >
> > Craig Matsuura - Principal Engineer
> > Control4
> > 11734 South Election Road - Suite 200
> > Salt Lake City, UT 84020-6432
> > PH: 801-523-3161
> > FX: 801-523-3199

--



Craig Matsuura - Principal Engineer
Control4
11734 South Election Road - Suite 200
Salt Lake City, UT 84020-6432
PH: 801-523-3161
FX: 801-523-3199

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