From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sagi Grimberg Subject: Re: [PATCH RFC v2 02/10] IB/core: Introduce Signature Verbs API Date: Sun, 3 Nov 2013 14:16:00 +0200 Message-ID: <52763E80.4000801@mellanox.com> References: <1383222255-22699-1-git-send-email-sagig@mellanox.com> <1383222255-22699-3-git-send-email-sagig@mellanox.com> <527429E7.7010705@acm.org> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <527429E7.7010705-HInyCGIudOg@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Bart Van Assche , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: oren-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org, tzahio-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org List-Id: linux-rdma@vger.kernel.org On 11/2/2013 12:23 AM, Bart Van Assche wrote: > On 31/10/2013 5:24, Sagi Grimberg wrote: >> + * @type3_inc_reftag: T10-DIF type 3 does not state >> + * about the reference tag, it is the user >> + * choice to increment it or not. > > Can you explain this further ? Does this mean that the HCA can check > whether the reference tags are increasing when receiving data for TYPE > 3 protection mode ? My understanding of SPC-4 is that the application > is free to use the reference tag in any way when using TYPE 3 > protection and hence that the HCA must not check whether the reference > tag is increasing for TYPE 3 protection. See e.g. > sd_dif_type3_get_tag() in drivers/scsi/sd_dif.c. > > Bart. As I understand TYPE 3, the reference tag is free for the application to use - which may choose to inc it each PI or not. This option allows the application to inc ref_tag in type 3. The DIF check is determined via check_mask. As I see it, correct use in case of DIF TYPE 3 is not to validate reference tag i.e. set REF_TAG bits in check_mask to zero. Sagi. -- 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