From mboxrd@z Thu Jan 1 00:00:00 1970 From: wsa@the-dreams.de (Wolfram Sang) Date: Thu, 2 Apr 2015 22:29:09 +0200 Subject: [PATCH] i2c: cadence: Handling Slave monitor mode In-Reply-To: References: <20150327153713.GC27238@katana> Message-ID: <20150402202909.GA3501@katana> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org > >> In slave monitor mode, the I2C interface is set up as a master and > >> continues to attempt a transfer to a particular slave until the > >> slave device responds with an ACK. > >> > >> Added this feature for zero length transfers enable the controller > >> for slave monitor interrupt and get the status. Disable the slave > >> monitor mode feature upon successful handling. > >> > >> Signed-off-by: Nava kishore Manne > >> Acked-by: Harini Katakam > > > > I am not sure this is going to work. > > > > How often is this access tried when there is no device? It should be > > tried only once. > > Once slave monitor is enabled in the host controller, it retries till there's an > ACK or slave monitor is disabled. The SW wont be involved and need not So, it is kind of flooding the bus until the timeout? That is not a single zero byte message. > be interrupted in this gap. The way this feature works in the controller though, > I'm afraid there's no way to distinguish between no slave/ busy slave. > The out is the software timeout in that case. > Please suggest how to use this feature better. I suggest to not use the feature and accept that this device cannot do zero byte length messages. Thanks, Wolfram -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 819 bytes Desc: Digital signature URL: