From patchwork Tue Oct 16 05:31:25 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Finn Thain X-Patchwork-Id: 10643125 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 53DDB112B for ; Tue, 16 Oct 2018 05:40:06 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4458E2980F for ; Tue, 16 Oct 2018 05:40:06 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3804429816; Tue, 16 Oct 2018 05:40:06 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D65B82983E for ; Tue, 16 Oct 2018 05:40:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728067AbeJPN2m (ORCPT ); Tue, 16 Oct 2018 09:28:42 -0400 Received: from kvm5.telegraphics.com.au ([98.124.60.144]:57196 "EHLO kvm5.telegraphics.com.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728054AbeJPN2F (ORCPT ); Tue, 16 Oct 2018 09:28:05 -0400 Received: by kvm5.telegraphics.com.au (Postfix, from userid 502) id 590B827FFA; Tue, 16 Oct 2018 01:39:21 -0400 (EDT) To: "James E.J. Bottomley" , "Martin K. Petersen" Cc: Michael Schmitz , Hannes Reinecke , linux-scsi@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org Message-Id: <41d39fdc25ed8ee608369a1ed956e635921dc2eb.1539667885.git.fthain@telegraphics.com.au> In-Reply-To: References: From: Finn Thain Subject: [PATCH v3 2/6] esp_scsi: Track residual for PIO transfers Date: Tue, 16 Oct 2018 16:31:25 +1100 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP If a target disconnects during a PIO data transfer the command may fail when the target reconnects: scsi host1: DMA length is zero! scsi host1: cur adr[04380000] len[00000000] The scsi bus is then reset. This happens because the residual reached zero before the transfer was completed. The usual residual calculation relies on the Transfer Count registers. That works for DMA transfers but not for PIO transfers. Fix the problem by storing the PIO transfer residual and using that to correctly calculate bytes_sent. Fixes: 6fe07aaffbf0 ("[SCSI] m68k: new mac_esp scsi driver") Tested-by: Stan Johnson Signed-off-by: Finn Thain Tested-by: Michael Schmitz --- Changed since v2: - Declare send_cmd_residual as u32 instead of int. --- drivers/scsi/esp_scsi.c | 1 + drivers/scsi/esp_scsi.h | 2 ++ drivers/scsi/mac_esp.c | 2 ++ 3 files changed, 5 insertions(+) diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c index c3fc34b9964d..9e5d3f7d29ae 100644 --- a/drivers/scsi/esp_scsi.c +++ b/drivers/scsi/esp_scsi.c @@ -1338,6 +1338,7 @@ static int esp_data_bytes_sent(struct esp *esp, struct esp_cmd_entry *ent, bytes_sent = esp->data_dma_len; bytes_sent -= ecount; + bytes_sent -= esp->send_cmd_residual; /* * The am53c974 has a DMA 'pecularity'. The doc states: diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h index 8163dca2071b..a77772777a30 100644 --- a/drivers/scsi/esp_scsi.h +++ b/drivers/scsi/esp_scsi.h @@ -540,6 +540,8 @@ struct esp { void *dma; int dmarev; + + u32 send_cmd_residual; }; /* A front-end driver for the ESP chip should do the following in diff --git a/drivers/scsi/mac_esp.c b/drivers/scsi/mac_esp.c index eb551f3cc471..71879f2207e0 100644 --- a/drivers/scsi/mac_esp.c +++ b/drivers/scsi/mac_esp.c @@ -427,6 +427,8 @@ static void mac_esp_send_pio_cmd(struct esp *esp, u32 addr, u32 esp_count, scsi_esp_cmd(esp, ESP_CMD_TI); } } + + esp->send_cmd_residual = esp_count; } static int mac_esp_irq_pending(struct esp *esp)