From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaly Kuznetsov Subject: Re: [PATCH v2] scsi: introduce short_inquiry flag for broken host adapters Date: Tue, 15 Sep 2015 16:27:03 +0200 Message-ID: <87k2rryczs.fsf@vitty.brq.redhat.com> References: <1441296673-14315-1-git-send-email-vkuznets@redhat.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1441296673-14315-1-git-send-email-vkuznets@redhat.com> (Vitaly Kuznetsov's message of "Thu, 3 Sep 2015 18:11:13 +0200") Sender: linux-kernel-owner@vger.kernel.org To: "James E.J. Bottomley" Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, "K. Y. Srinivasan" , Long Li , Dexuan Cui List-Id: linux-scsi@vger.kernel.org Vitaly Kuznetsov writes: > Some host adapters (e.g. Hyper-V storvsc) are known for not respecting the > SPC-2/3/4 requirement for 'INQUIRY data (see table ...) shall contain at > least 36 bytes'. As a result we get tons on 'scsi 0:7:1:1: scsi scan: > INQUIRY result too short (5), using 36' messages on console. This can be > problematic for slow consoles. Introduce short_inquiry host template flag > to avoid printing error messages for such adapters. > > Signed-off-by: Vitaly Kuznetsov > --- > Changes since v1: > - This is a successor of previously sent "scsi_scan: move 'INQUIRY result > too short' message to debug level" patch. Instead of moving the message > to debug level for all adapters introduce a special 'short_inquiry' flag > for host template [inspired by James Bottomley]. James, sorry for the ping but can you please let me know your opinion? This is not a 'cosmetic fix', serial port on Hyper-V is extremely slow and users get softlockups just because we output too much. Here is a freshly booted guest with SCSI and FC adapters connected: # dmesg | grep -c INQUIRY 2076 (my other pernding '[PATCH] scsi_scan: don't dump trace when scsi_prep_async_scan() is called twice' is related to the same issue). See also: https://lkml.org/lkml/2015/9/6/119 Thanks, [...] -- Vitaly