From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 52E5DC43331 for ; Mon, 11 Nov 2019 08:47:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 27B9B20869 for ; Mon, 11 Nov 2019 08:47:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726845AbfKKIrX (ORCPT ); Mon, 11 Nov 2019 03:47:23 -0500 Received: from smtpq4.tb.mail.iss.as9143.net ([212.54.42.167]:33998 "EHLO smtpq4.tb.mail.iss.as9143.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726939AbfKKIrX (ORCPT ); Mon, 11 Nov 2019 03:47:23 -0500 Received: from [212.54.42.137] (helo=smtp6.tb.mail.iss.as9143.net) by smtpq4.tb.mail.iss.as9143.net with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1iU5M1-0001mH-3w; Mon, 11 Nov 2019 09:47:21 +0100 Received: from mail-wr1-f45.google.com ([209.85.221.45]) by smtp6.tb.mail.iss.as9143.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1iU5M0-0001uS-W9; Mon, 11 Nov 2019 09:47:21 +0100 Received: by mail-wr1-f45.google.com with SMTP id z10so8316903wrs.12; Mon, 11 Nov 2019 00:47:20 -0800 (PST) X-Gm-Message-State: APjAAAVdkduD1YyplcDfELa+cQEQJ4THU49SR+rkwsevBTlZZn5dOknh zxsh1WrQkB7G2O62jHIJaAYCOlCRPxIbdhNg1Bo= X-Google-Smtp-Source: APXvYqxytncLcfi7aeYlcB1IxU7tMFvoLFaFecX1/Na+heYEi6TijmtyvmgPz9vDvICRH+4e7UxekGqVxzWn/OJPiJE= X-Received: by 2002:a5d:4146:: with SMTP id c6mr18862537wrq.250.1573462040680; Mon, 11 Nov 2019 00:47:20 -0800 (PST) MIME-Version: 1.0 References: <20191109191400.8999-1-jongk@linux-m68k.org> <1573330351.3650.4.camel@linux.ibm.com> <6b914b12-cbc7-6fe6-7cba-3e89b2f6f19b@gmail.com> <8c356175-e490-68c0-6114-5192eedc3a4f@gmail.com> In-Reply-To: <8c356175-e490-68c0-6114-5192eedc3a4f@gmail.com> From: Kars de Jong Date: Mon, 11 Nov 2019 09:47:09 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] zorro_esp: increase maximum dma length to 65536 bytes To: Michael Schmitz Cc: James Bottomley , "Martin K. Petersen" , linux-scsi@vger.kernel.org, linux-m68k@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-SourceIP: 209.85.221.45 X-Authenticated-Sender: karsdejong@home.nl (via SMTP) X-Ziggo-spambar: / X-Ziggo-spamscore: 0.0 X-Ziggo-spamreport: CMAE Analysis: v=2.3 cv=WMwBoUkR c=1 sm=1 tr=0 a=9+rZDBEiDlHhcck0kWbJtElFXBc=:19 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=IkcTkHD0fZMA:10 a=MeAgGD-zjQ4A:10 a=pGLkceISAAAA:8 a=xNf9USuDAAAA:8 a=hJ9ZtYj-RI1EAQISWCsA:9 a=EE2vHBecVcuu-u5a:21 a=SQQkrWvguoklZZ3D:21 a=QEXdDO2ut3YA:10 a=SEwjQc04WA-l_NiBhQ7s:22 X-Ziggo-Spam-Status: No Sender: linux-m68k-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-m68k@vger.kernel.org Hi Michael, Op zo 10 nov. 2019 om 20:26 schreef Michael Schmitz : > >>> case for any of the cards the zorro_esp drives, it might be better to > >>> lower the max length to 61440 (64k-4k) so the residual is a page. > >> For the benefit of keeping the code simple, and avoid retesting the > >> fastlane board, that might indeed be the better solution. > > > > But it's slower... :-P > > > I wonder what max. transfer size had been used so far, in the majority > of cases. I hadn't observed this bug in my tests of the ESP driver on > elgar. So it might not matter so much in practice. Does Elgar indeed have a Blizzard 2060 as https://wiki.debian.org/M68k/Autobuilder says? If it does, it does surprise me that it works, since the DMA engine appears to be very much like the one of the Blizzard 1230 (including the >> 1 of the address). Even when just loading bash on my system, there were many 65535-and-then-1 byte transfers. It may of course depend on how fragmented your disk is. > > Also, I may be adding another board-specific version for the Blizzard > > 12x0 IV to enable 24-bit transfers, like the am53c974 driver does, in > > a later patch. > > If we can differentiate between the Mark IV board and the Mark II board > in a reliable way, fine. I can't remember whether I've had a report on > that ever. They have a different Zorro ID, so that should not be a problem. By the way, do you remember why you chose to not use the full Zorro IDs for the various SCSI boards asdefined in zorro_ids.h but only the manufacturer defines? Kind regards, Kars.