From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Date: Fri, 15 Feb 2019 09:52:39 +0100 Subject: [PATCH v2] i2c: aspeed: Add multi-master use case support In-Reply-To: <20190211185444.4965-1-jae.hyun.yoo@linux.intel.com> References: <20190211185444.4965-1-jae.hyun.yoo@linux.intel.com> Message-ID: <20190215085239.v5cjmcef2q62xiyl@ninjato> List-Id: To: linux-aspeed@lists.ozlabs.org MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Mon, Feb 11, 2019 at 10:54:44AM -0800, Jae Hyun Yoo wrote: > In multi-master environment, this driver's master cannot know > exactly when a peer master sends data to this driver's slave so > cases can be happened that this master tries sending data through > the master_xfer function but slave data from a peer master is still > being processed or slave xfer is started by a peer immediately > after it queues a master command. To support multi-master use cases > properly, this H/W provides arbitration in physical level and it > provides priority based command handling too to avoid conflicts in > multi-master environment, means that if a master and a slave events > happen at the same time, H/W will handle a higher priority event > first and a pending event will be handled when bus comes back to > the idle state. > > To support this H/W feature properly, this patch adds the 'pending' > state of master and its handling code so that the pending master > xfer can be continued after slave operation properly. > > Signed-off-by: Jae Hyun Yoo > Reviewed-by: Brendan Higgins Applied to for-next, thanks! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: