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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2A861C433EF for ; Tue, 21 Dec 2021 11:47:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237243AbhLULrZ (ORCPT ); Tue, 21 Dec 2021 06:47:25 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233650AbhLULrX (ORCPT ); Tue, 21 Dec 2021 06:47:23 -0500 Received: from mail-lf1-x131.google.com (mail-lf1-x131.google.com [IPv6:2a00:1450:4864:20::131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4D94C061574 for ; Tue, 21 Dec 2021 03:47:22 -0800 (PST) Received: by mail-lf1-x131.google.com with SMTP id bu9so7166982lfb.7 for ; Tue, 21 Dec 2021 03:47:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=5iHMu2RceiYZBlM7VQJrpbt7pv1hPIsprESHZDmwuTY=; b=SlMtEqXNa+jqXV5oiXirDiiBXnO7KyZtnJXamN8ehWQqFiIXZmDb8rw/p/J4AMpQ76 8Y+bMR0/4sYPYk7Tv2e+ympFkAGUdXgWbUPNO0jU79aRV0/HF/K1XFznhJ+IaIMRQxiZ CatQl76QNhO4jtpNLXQo98+uPSloV0zA44ItlE4WKMGVcjtxVNstRQ3LdpjrmJC7bFLl U0uKoQZw1oKD/M0agtCq6G2MZlWhMcXhwpqp+BQ7aJfrZIUA5p0i7BCPRk74lcbbm3Cf 2e25EO8OwWB+eIMtIpePRINnIYCmpCjsMuLuI2ksXr750wX/HIoUxZJytJCxUY7BJKI+ xqsQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=5iHMu2RceiYZBlM7VQJrpbt7pv1hPIsprESHZDmwuTY=; b=WBQBSKs+LYZZYfVERr8nxeo4DOwF1sH+zSJ9xYJPfhdI0SHOh8vzPnAt19eieAiUqX Bi9detJcQROlCLLqbxl/DcVDTkqIOMoNza6zoBhapo5+60tCI8+QKsTTPJKHT8d1jWO0 0FutWBAWhLoslSidSsx4dhUeQK7+l04LE4Lu9ydcHx8vXs0AhW5gKvbpdmnd4MxtejWM sgbcn0C3qPp4Z3QwzLxPMu/0meoPW+dztCbJgrBZfDFqw1zEeBpa5iasy0Hsk1Yy4ajq 6yAouFAW3TwMpC1Qy/cxWi2poB1bpcreB4atxdTdNjndfwwNV+7x1FR50U2qb+pM/5Kb 7WbA== X-Gm-Message-State: AOAM531BAN/Fvd+4aWIXILOTpkC+8z0eSz2ad54wF8tzmr9/w9Rl0guO z2zOxbQ0LpNRvg+jqw8qOnRCft7XgfDFsWGWDVGisQ== X-Google-Smtp-Source: ABdhPJz5e1F2UioOi7x20744XGEveL1bhBJE+6hcEi+URVa1/5tCLuhCcxduegYHFw/t0tJUUmwS8b2xFV54ZZY88MA= X-Received: by 2002:a05:6512:4015:: with SMTP id br21mr2819857lfb.233.1640087241138; Tue, 21 Dec 2021 03:47:21 -0800 (PST) MIME-Version: 1.0 References: <5542600.DvuYhMxLoT@kreacher> In-Reply-To: <5542600.DvuYhMxLoT@kreacher> From: Ulf Hansson Date: Tue, 21 Dec 2021 12:46:44 +0100 Message-ID: Subject: Re: [PATCH] PM: runtime: Simplify locking in pm_runtime_put_suppliers() To: "Rafael J. Wysocki" Cc: Linux PM , LKML Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 17 Dec 2021 at 20:16, Rafael J. Wysocki wrote: > > From: Rafael J. Wysocki > > Notice that pm_runtime_put_suppliers() cannot be called with > disabled interrupts, because it may sleep (due to the device > links read locking in the non-SRCU case), and so it can use > spin_lock_irq() and spin_unlock_irq() for the locking. > > Update the function accordingly and while at it move the "put" > local variable in it into the inner block where it is used. > > This change is not expected to have any visible functional impact. > > Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Kind regards Uffe > --- > drivers/base/power/runtime.c | 12 ++++++++---- > 1 file changed, 8 insertions(+), 4 deletions(-) > > Index: linux-pm/drivers/base/power/runtime.c > =================================================================== > --- linux-pm.orig/drivers/base/power/runtime.c > +++ linux-pm/drivers/base/power/runtime.c > @@ -1748,8 +1748,6 @@ void pm_runtime_get_suppliers(struct dev > void pm_runtime_put_suppliers(struct device *dev) > { > struct device_link *link; > - unsigned long flags; > - bool put; > int idx; > > idx = device_links_read_lock(); > @@ -1757,11 +1755,17 @@ void pm_runtime_put_suppliers(struct dev > list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, > device_links_read_lock_held()) > if (link->supplier_preactivated) { > + bool put; > + > link->supplier_preactivated = false; > - spin_lock_irqsave(&dev->power.lock, flags); > + > + spin_lock_irq(&dev->power.lock); > + > put = pm_runtime_status_suspended(dev) && > refcount_dec_not_one(&link->rpm_active); > - spin_unlock_irqrestore(&dev->power.lock, flags); > + > + spin_unlock_irq(&dev->power.lock); > + > if (put) > pm_runtime_put(link->supplier); > } > > >