From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Thumshirn Subject: Re: [PATCH 2/6] scsi: hisi_sas: workaround a SoC SATA IO processing bug Date: Mon, 10 Apr 2017 16:07:00 +0200 Message-ID: <20170410140700.GT1978@linux-x5ow.site> References: <1491830521-21437-1-git-send-email-john.garry@huawei.com> <1491830521-21437-3-git-send-email-john.garry@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <1491830521-21437-3-git-send-email-john.garry@huawei.com> Sender: linux-kernel-owner@vger.kernel.org To: John Garry Cc: jejb@linux.vnet.ibm.com, martin.petersen@oracle.com, john.garry2@mail.dcu.ie, linuxarm@huawei.com, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, zhangfei.gao@linaro.org, Xiaofei Tan List-Id: linux-scsi@vger.kernel.org On Mon, Apr 10, 2017 at 09:21:57PM +0800, John Garry wrote: > From: Xiaofei Tan > > This patch provides a workaround a SoC bug where SATA IPTTs for > different devices may conflict. > > The workaround solution requests the following: > 1. SATA device id must be even and not equal to SAS IPTT. > 2. SATA device can not share the same IPTT with other SAS or > SATA device. > > Besides we shall consider IPTT value 0 is reserved for another SoC > bug (STP device open link at firstly after SAS controller reset). > > To sum up, the solution is: > Each SATA device uses independent and continuous 32 even IPTT from > 64 to 4094, then v2 hw can only support 63 SATA devices. > All SAS device(SSP/SMP devices) share odd IPTT value from 1 to > 4095. > > Signed-off-by: Xiaofei Tan > Signed-off-by: John Garry > --- Reviewed-by: Johannes Thumshirn -- Johannes Thumshirn Storage jthumshirn@suse.de +49 911 74053 689 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: Felix Imendörffer, Jane Smithard, Graham Norton HRB 21284 (AG Nürnberg) Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850