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=-5.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 4FE88C4CEC8 for ; Thu, 12 Sep 2019 13:44:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FC5620856 for ; Thu, 12 Sep 2019 13:44:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732245AbfILNoT convert rfc822-to-8bit (ORCPT ); Thu, 12 Sep 2019 09:44:19 -0400 Received: from mail-pg1-f196.google.com ([209.85.215.196]:37631 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732239AbfILNoT (ORCPT ); Thu, 12 Sep 2019 09:44:19 -0400 Received: by mail-pg1-f196.google.com with SMTP id c17so5768084pgg.4 for ; Thu, 12 Sep 2019 06:44:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=ceNPWcWTipfAfeKAaiTT4udHgEwkImit4TBFNaxXyew=; b=lNQe42uWsK1+IEwGyghM/3rXiRxbcJkDuVTG9g+2E9RJg0tgPmJkgREYbFiyREYKPJ XBekPNhewiv7UcZrgB8g71xiCoZIBRILoCPupSSVmw2zypG63+S39BHBAa53Fp+ol7Rz Ioh62YRTLbU7637AYh1Z1DqRIU8WLDsvuUvLBnJj2HoRrktfgUi6wOJRbiYMheh4QLy7 vpVUx75G0u1Jc1WZD7IoXxfLSrHPz6Vvv53uKKcpxA/N4/nThPPdu2FDvBa2aYtpvyyv h3vyWFxTlZUz9D9uyxLegwzUD30N/myGK5LYsVvu3RVScwfjJFY4tveeI3asQERyaM2h +Z2w== X-Gm-Message-State: APjAAAW1uAhvNx69BAEK5hRe6cseoUSk6KD6k3aQqYi2+fFvld+q7+Nz LkeNXrBcSo9XfhlTvKD3HB6dh7OSJ/rjfQ== X-Google-Smtp-Source: APXvYqzB9SsBEHXbRoDazbOUKTlPNiidOJt/lTTfbHQKmD4OVAcRrfttF0ZrGy/78yadGVxkdsVRGA== X-Received: by 2002:a65:430a:: with SMTP id j10mr39157233pgq.374.1568295858937; Thu, 12 Sep 2019 06:44:18 -0700 (PDT) Received: from [172.19.249.100] ([38.98.37.138]) by smtp.gmail.com with ESMTPSA id s18sm32320324pfh.0.2019.09.12.06.43.52 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 12 Sep 2019 06:44:18 -0700 (PDT) Subject: Re: [PATCH v2 1/3] scsi: core: allow auto suspend override by low-level driver To: Stanley Chu , linux-scsi@vger.kernel.org, martin.petersen@oracle.com, avri.altman@wdc.com, alim.akhtar@samsung.com, pedrom.sousa@synopsys.com, sthumma@codeaurora.org, jejb@linux.ibm.com Cc: linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org, matthias.bgg@gmail.com, evgreen@chromium.org, beanhuo@micron.com, marc.w.gonzalez@free.fr, subhashj@codeaurora.org, vivek.gautam@codeaurora.org, kuohong.wang@mediatek.com, peter.wang@mediatek.com, chun-hung.wu@mediatek.com, andy.teng@mediatek.com References: <1568270135-32442-1-git-send-email-stanley.chu@mediatek.com> <1568270135-32442-2-git-send-email-stanley.chu@mediatek.com> From: Bart Van Assche Message-ID: <485731ed-d455-dbb2-0cd5-3110ff14f6b7@acm.org> Date: Thu, 12 Sep 2019 14:43:44 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <1568270135-32442-2-git-send-email-stanley.chu@mediatek.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8BIT Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org On 9/12/19 7:35 AM, Stanley Chu wrote: > diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c > index 64c96c7828ee..461aafadd208 100644 > --- a/drivers/scsi/scsi_sysfs.c > +++ b/drivers/scsi/scsi_sysfs.c > @@ -1300,7 +1300,8 @@ int scsi_sysfs_add_sdev(struct scsi_device *sdev) > device_enable_async_suspend(&sdev->sdev_gendev); > scsi_autopm_get_target(starget); > pm_runtime_set_active(&sdev->sdev_gendev); > - pm_runtime_forbid(&sdev->sdev_gendev); > + if (sdev->rpm_autosuspend_delay < 0) > + pm_runtime_forbid(&sdev->sdev_gendev); > pm_runtime_enable(&sdev->sdev_gendev); > scsi_autopm_put_target(starget); So we have a single new struct member, rpm_autosuspend_delay, that controls two different behaviors: (a) whether or not runtime suspend is enabled at device creation time and (b) the power management autosuspend delay. I don't like this. Should two separate variables be introduced instead of using a single variable to control both behaviors? > diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h > index 202f4d6a4342..133b282fae5a 100644 > --- a/include/scsi/scsi_device.h > +++ b/include/scsi/scsi_device.h > @@ -199,7 +199,7 @@ struct scsi_device { > unsigned broken_fua:1; /* Don't set FUA bit */ > unsigned lun_in_cdb:1; /* Store LUN bits in CDB[1] */ > unsigned unmap_limit_for_ws:1; /* Use the UNMAP limit for WRITE SAME */ > - > + int rpm_autosuspend_delay; > atomic_t disk_events_disable_depth; /* disable depth for disk events */ > > DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */ > Since the default value for the autosuspend delay is the same for all SCSI devices attached to a SCSI host is the same, please add a variable with the same name in the SCSI host template and use that value as the default value for SCSI devices. If the rpm_autosuspend_delay variable only occurs in struct scsi_device then LLD authors are forced to introduce a slave_configure function. Introducing such a function can be avoided if the default autosuspend delay can be specified in the host template. Bart.