From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753135AbbLVHbP (ORCPT ); Tue, 22 Dec 2015 02:31:15 -0500 Received: from mx2.suse.de ([195.135.220.15]:42958 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751166AbbLVHbO (ORCPT ); Tue, 22 Dec 2015 02:31:14 -0500 Subject: Re: [PATCH v3 35/77] ncr5380: Dont wait for BUS FREE after disconnect To: Finn Thain , "James E.J. Bottomley" , Michael Schmitz , linux-m68k@vger.kernel.org, linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, "Martin K. Petersen" References: <20151222011737.980475848@telegraphics.com.au> <20151222011747.535983710@telegraphics.com.au> From: Hannes Reinecke Message-ID: <5678FC3F.5040507@suse.de> Date: Tue, 22 Dec 2015 08:31:11 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <20151222011747.535983710@telegraphics.com.au> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/22/2015 02:18 AM, Finn Thain wrote: > When there is a queued command and no connected command, NCR5380_select() > is called and arbitration begins. The chip waits for BUS FREE once the > MR_ARBITRATE bit in the mode register is enabled. That means there is > no need to wait for BUS FREE after disconnecting. > > There is presently no polling for BUS FREE after sending an ABORT or > other message that might lead to disconnection. It only happens after > COMMAND COMPLETE or DISCONNECT messages, which seems inconsistent. > Remove the polling for !BSY in the COMMAND COMPLETE and DISCONNECT > cases. > > BTW, the comments say "avoid nasty timeouts" and perhaps BUS FREE polling > was somehow helpful back in Linux v0.99.14u, when it was introduced. > The relevant timeout is presently 1 second (for bus arbitration). > > Signed-off-by: Finn Thain > > --- > drivers/scsi/NCR5380.c | 7 ------- > drivers/scsi/atari_NCR5380.c | 11 ----------- > 2 files changed, 18 deletions(-) > Reviewed-by: Hannes Reinecke Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@suse.de +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)