From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6EBB91863 for ; Wed, 28 Dec 2022 14:51:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB102C433D2; Wed, 28 Dec 2022 14:51:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672239093; bh=Vx/CWeov4R/QTrvpkWvsjKhPQKKmAJchvIemktCAaFw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=u0kTOHRiRQWaMb7IgHdG99uV8VQLHKYpb4i2gxZ5Yn7vrlQ4L9h5x8CcjbJmiEUtw mhZGDdtOgDlDQCZnsD6smXIXKEWqjZo+WHUwVKSoJq7wPCnMv6+u8Ojh8GBLXiPwxJ tL1UyAl4ZXaOEe85Kn/UNOdGQ//9dVrOMUtgQrZ8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Rafael J. Wysocki" , Adrian Hunter , Sasha Levin Subject: [PATCH 5.15 126/731] PM: runtime: Do not call __rpm_callback() from rpm_idle() Date: Wed, 28 Dec 2022 15:33:53 +0100 Message-Id: <20221228144300.204321220@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144256.536395940@linuxfoundation.org> References: <20221228144256.536395940@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Rafael J. Wysocki [ Upstream commit bc80c2e438dcbfcf748452ec0f7ad5b79ff3ad88 ] Calling __rpm_callback() from rpm_idle() after adding device links support to the former is a clear mistake. Not only it causes rpm_idle() to carry out unnecessary actions, but it is also against the assumption regarding the stability of PM-runtime status across __rpm_callback() invocations, because rpm_suspend() and rpm_resume() may run in parallel with __rpm_callback() when it is called by rpm_idle() and the device's PM-runtime status can be updated by any of them. Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com Signed-off-by: Rafael J. Wysocki Reviewed-by: Adrian Hunter Signed-off-by: Sasha Levin --- drivers/base/power/runtime.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 3179c9265471..c1142a7a4fe6 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -484,7 +484,17 @@ static int rpm_idle(struct device *dev, int rpmflags) dev->power.idle_notification = true; - retval = __rpm_callback(callback, dev); + if (dev->power.irq_safe) + spin_unlock(&dev->power.lock); + else + spin_unlock_irq(&dev->power.lock); + + retval = callback(dev); + + if (dev->power.irq_safe) + spin_lock(&dev->power.lock); + else + spin_lock_irq(&dev->power.lock); dev->power.idle_notification = false; wake_up_all(&dev->power.wait_queue); -- 2.35.1