From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tao Ren Subject: Re: [PATCH] i2c: aspeed: fix master pending state handling Date: Thu, 10 Oct 2019 01:26:49 +0000 Message-ID: <43ab0316-78dd-b7b0-c04e-e039d38c3d45@fb.com> References: <20191009212034.20325-1-jae.hyun.yoo@linux.intel.com> <20191010003234.GA12710@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20191010003234.GA12710@google.com> Content-Language: en-US Content-ID: <3DC2428602E08C4F8C65A1DA359F1D88@namprd15.prod.outlook.com> 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: Brendan Higgins , Jae Hyun Yoo Cc: Mark Rutland , "devicetree@vger.kernel.org" , "linux-aspeed@lists.ozlabs.org" , Wolfram Sang , Andrew Jeffery , Benjamin Herrenschmidt , "openbmc@lists.ozlabs.org" , "linux-i2c@vger.kernel.org" , Rob Herring , Joel Stanley , "linux-arm-kernel@lists.infradead.org" , Cedric Le Goater List-Id: devicetree@vger.kernel.org On 10/9/19 5:32 PM, Brendan Higgins wrote: > On Wed, Oct 09, 2019 at 02:20:34PM -0700, 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 > > Reviewed-by: Brendan Higgins > > We don't have any multi-master setups, can we get a Tested-by? I've applied the patch to my tree and I'm looking for a minipack BMC (milti-master) to test the patch. Will come back with results tomorrow. Cheers, Tao > Wolfram, since this is a bugfix, can we get this in 5.4? > > Thanks! >