Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756559Ab3GQQVv (ORCPT ); Wed, 17 Jul 2013 12:21:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39353 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755052Ab3GQQVs (ORCPT ); Wed, 17 Jul 2013 12:21:48 -0400 Date: Wed, 17 Jul 2013 18:19:10 +0200 From: Alexander Gordeev To: "Nicholas A. Bellinger" Cc: Tejun Heo , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org, Jeff Garzik , Jens Axboe , linux-scsi Subject: Re: [PATCH RESEND 0/1] AHCI: Optimize interrupt processing Message-ID: <20130717161909.GB21468@dhcp-26-207.brq.redhat.com> References: <20130521235003.GE6985@mtj.dyndns.org> <20130522143923.GD19383@dhcp-26-207.brq.redhat.com> <20130522170305.GD9563@kernel.dk> <20130711102630.GA11133@dhcp-26-207.brq.redhat.com> <1373583637.7397.370.camel@haakon3.risingtidesystems.com> <20130712074559.GA8727@dhcp-26-207.brq.redhat.com> <1373692812.7397.625.camel@haakon3.risingtidesystems.com> <20130716183207.GA6402@dhcp-26-207.brq.redhat.com> <1374010683.7397.880.camel@haakon3.risingtidesystems.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1374010683.7397.880.camel@haakon3.risingtidesystems.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1817 Lines: 47 On Tue, Jul 16, 2013 at 02:38:03PM -0700, Nicholas A. Bellinger wrote: > [ 7.927818] scsi_execute(): Calling blk_mq_free_request >>> > [ 7.927826] scsi 0:0:0:0: Direct-Access ATA ST9500530NS CC03 PQ: 0 ANSI: 5 > > OK, so INQUIRY response payload is looking as expected here. Yep. It is not on the top of my head, but I remember something like INQUIRYs are emulated and thus do not have payload. > [ 7.927960] sd 0:0:0:0: [sda] Sector size 0 reported, assuming 512. > [ 7.927964] sd 0:0:0:0: [sda] 1 512-byte logical blocks: (512 B/512 B) > [ 7.927965] sd 0:0:0:0: [sda] 0-byte physical blocks > > Strange.. READ_CAPACITY appears to be returning a payload as zeros..? Yep. Because blk_execute_rq() does not put the proper callback and data do not get copied from sg's to bounce buffer. That is why I tried to use blk_mq_execute_rq() instead. Once I do that, data start getting read and booting stops elsewhere. Of course, I was suspecting that change alone is not valid and wondered about the status of scsi-mq in the first place, and if more changes are coming. So I it turns out "req->errors + req->resid_len" issue (you described earlier) needs to be addressed before going forward with libata (only?). > Not sure why yet some control CDBs are getting back the expected > payload, while others are returning zeros.. Bio buffers do not get updated from callback. > Also, looking at the included stack back-trace: [...] Thanks a lot for these and other your comments, Nicholas! -- Regards, Alexander Gordeev agordeev@redhat.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/