From mboxrd@z Thu Jan 1 00:00:00 1970 From: Or Gerlitz Subject: Re: [RFC PATCH 03/16] ib/mad: Add check for jumbo MADs support on a device Date: Thu, 27 Nov 2014 13:47:16 +0200 Message-ID: <54770F44.2090909@mellanox.com> References: <1415908465-24392-1-git-send-email-ira.weiny@intel.com> <1415908465-24392-4-git-send-email-ira.weiny@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1415908465-24392-4-git-send-email-ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org, roland-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 11/13/2014 9:54 PM, ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org wrote: > Add a device capability flag for OPA devices to signal their support of "jumbo" > MADs. > > Check for IB_DEVICE_JUMBO_MAD_SUPPORT in the device capabilities and if > supported mark the special QPs created. Ira, Few comments here, the device capability is OK, specifically if it helps for the mad layer logic to be simpler and/or more robust. You should add device attribute telling what is the size of MADs supported by the device, I think the IBTA mandated 256Band in the OPA case, the driver will fill there 2k. You can't just state that (jumbo == 2k) and go to complete design/changes which use this hard-coded assumption. You need to see how to re-spin this series w.o this assumption. I find it very annoying that upper level drivers replicate in different ways elements from the IB device attributes returned by ib_query_device. I met that in multiple drivers and upcoming designs for which I do code review. Are you up to come up with a patch that caches the device attributes on the device structure? if not, I can do that.. and have your code to see it. Also, I would go and unify (squash) this patch and the preceding one. -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html