From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jae Hyun Yoo Subject: Re: [PATCH] i2c: aspeed: fix master pending state handling Date: Thu, 10 Oct 2019 16:52:41 -0700 Message-ID: <4ca4083d-23ff-0475-f5fd-ec3745b440b2@linux.intel.com> References: <20191009212034.20325-1-jae.hyun.yoo@linux.intel.com> <49244d71-cbc3-f2ae-97ac-74b5f68a4816@fb.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <49244d71-cbc3-f2ae-97ac-74b5f68a4816@fb.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Tao Ren , Brendan Higgins , Wolfram Sang , Benjamin Herrenschmidt , Joel Stanley , Rob Herring , Mark Rutland , Andrew Jeffery , Cedric Le Goater Cc: "devicetree@vger.kernel.org" , "linux-aspeed@lists.ozlabs.org" , "linux-i2c@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "openbmc@lists.ozlabs.org" List-Id: devicetree@vger.kernel.org On 10/10/2019 4:29 PM, Tao Ren wrote: > On 10/9/19 2:20 PM, Jae Hyun Yoo wrote: >> In case of master pending state, it should not trigger a master >> command, otherwise data could be corrupted because this H/W shares >> the same data buffer for slave and master operations. It also means >> that H/W command queue handling is unreliable because of the buffer >> sharing issue. To fix this issue, it clears command queue if a >> master command is queued in pending state to use S/W solution >> instead of H/W command queue handling. Also, it refines restarting >> mechanism of the pending master command. >> >> Fixes: 2e57b7cebb98 ("i2c: aspeed: Add multi-master use case support") >> Signed-off-by: Jae Hyun Yoo > > Tested-by: Tao Ren > > Tested the patch on Facebook Minipack BMC (multi-master i2c-0 environment) and > everything looks good to me. Thanks for sharing the test result and your code reviews. Best, Jae