From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Fri, 3 Apr 2015 22:18:46 +0200 Subject: [PATCH v3 4/5] i2c: davinci: use bus recovery infrastructure In-Reply-To: <550C67D6.3080909@linaro.org> References: <1417448047-15236-1-git-send-email-grygorii.strashko@ti.com> <1417448047-15236-5-git-send-email-grygorii.strashko@ti.com> <20150318203151.GA12072@katana> <550C67D6.3080909@linaro.org> Message-ID: <20150403201846.GH2016@katana> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > > The I2C specs say in 3.1.16 that the recovery procedure should be used > > when SDA is stuck low. So, I do wonder if we should apply the recovery > > after a timeout. Stuck SDA might be one reason for timeout, but there > > may be others... > > This is ancient code. And regarding your question - > Might be it would be reasonable to add call of > i2c_davinci_wait_bus_not_busy() at the end of i2c_davinci_xfer()? > This way we will wait for Bus Free before performing recovery. That might be an improvement, but the generic question still remains: Is a timeout a reason for recovery? SDA stuck low is one reason for a timeout. I have problems making up my mind here between being pragmatic and being in accordance with the specs. > Of course, i2c_davinci_wait_bus_not_busy() has to be fixed first > as proposed by Alexander Sverdlin here: > https://patchwork.ozlabs.org/patch/448994/. Okay, good that you said it. So I'll give his patch series priority over this one. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: