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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8302CC79F9F for ; Thu, 10 Sep 2026 18:50:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:Message-ID:References:In-Reply-To:Subject:Cc:To:From:Date: MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ILJuufaqNcUzTTR4FwZhEK5XMtJpPKS2KUNnrZzHEu0=; b=V73ajXGhqL5m0utkGOLgBUqlPY mPzHekVIw5aAluDoB/RDi8Ljv/fCLORUj2J7ExjqLNXrXCOG/x2zV+IYr4jpVS4nutUDVQJB7/yqD f4/UlUed8auHRLKwp/Wt541WpFU8Mip/EJmN9wO6lNCPbo3UTYcPQDn9EAjlV+TNGOLxoe8TP7pOx dq2yuYfDWNJp2N3y99f+Vb04sduNh5963idp56xMYkmMFBqkNrdAF4zh84FCuAmy+kCHTHwL29rZZ d4SnV8xtSHr65kegSP64QSeZzJBdCuLNsjveZYpFAHnZyGbeARRA8mNmhjx4kErizugJo56rL/AUw e1Pz2i9Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4jrF-0000000FBUF-3aPA; Thu, 10 Sep 2026 18:50:49 +0000 Received: from mail.tipi-net.de ([2a03:4000:43:185::1]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x4jrD-0000000FBTq-2hHK for linux-arm-kernel@lists.infradead.org; Thu, 10 Sep 2026 18:50:49 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 5A255A4C11; Thu, 10 Sep 2026 20:50:30 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=tipi-net.de; s=dkim; t=1789066243; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=ILJuufaqNcUzTTR4FwZhEK5XMtJpPKS2KUNnrZzHEu0=; b=LIEWtQn2q2K3wNf8lJTrV4feoBXYb0rEHyO4tcZn7i7/YuHwHcEDoJA88/HjoX9w6HWV8J LaVkYnSs42GL5ueLXk3pjg5zvGIHCTAKsohp25xpUpfpyj3pKAKkJrtcU/daigWszK8A5i aWW+qnasQida1DBitAlPyOpV6tS8KA+WKjFZ/h6SmxheeI0iq5vHf/lVAMtHgcJUYESe5U IB0emU8VASWIbX1M4KtgvVh9FOryGT7CAh+KKRGG/LAiV1aC8eguhGO0FUm+20UqJv7n1n jPRWWfb9XQ/Srac3PRgVj6KYO0TyGAGWhOEppfbf2EOYd3MLTfA/zDsgmg+uXg== MIME-Version: 1.0 Date: Thu, 10 Sep 2026 20:50:30 +0200 From: Nicolai Buchwitz To: Maxime Chevallier Cc: Andrew Lunn , davem@davemloft.net, Eric Dumazet , Jakub Kicinski , Paolo Abeni , Russell King , Heiner Kallweit , =?UTF-8?Q?Alexis_Lothor=C3=A9?= , Maxime Coquelin , Alexandre Torgue , Emil Renner Berthing , Minda Chen , Neil Armstrong , Kevin Hilman , Jerome Brunet , Martin Blumenstingl , Jan Petrous , Ovidiu Panait , Jose.Abreu@synopsys.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, thomas.petazzoni@bootlin.com, linux-arm-kernel@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, PKneuper@dspace.de, David Laight Subject: Re: [PATCH net v2 2/6] net: stmmac: selftests: Validate EEE based on the actual LPI timer value In-Reply-To: <20260910151404.976753-3-maxime.chevallier@bootlin.com> References: <20260910151404.976753-1-maxime.chevallier@bootlin.com> <20260910151404.976753-3-maxime.chevallier@bootlin.com> Message-ID: <6af83ee5b9ddeeebcc6e4cc29989b856@tipi-net.de> X-Sender: nb@tipi-net.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260910_115047_868021_B8122009 X-CRM114-Status: GOOD ( 17.41 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Maxime, Sorry for the noise, but after having a second look, there is something which I think should be discussed at least. On 10.9.2026 17:13, Maxime Chevallier wrote: > The EEE selftest is a 2-step test : > - It validates that we enter in LPI mode with the > irq_tx_path_in_lpi_mode_n counter > - It then validates that we exit LPI when sending a frame, with the > irq_tx_path_exit_lpi_mode_n counter. > > The current state of the test lacks 2 main things : > > - We don't know exactly when was the previous frame sent (it's from > the > previous selftest) > > - The timeout is hardcoded, while the LPI is entered after a > user-configurable delay. On top of that, the timeout loop uses a > pre-decrement iterator (--retries) that actually only iterate nine > times, so 900ms while the default LPI value is 1 second. > > Let's therefore make it more deterministic : > > - Send a frame at the beginning of the test > - Wait for more than the lpi timer value, we timeout after about twice > the value, > - Then send another frame, and verify that we do go out of LPI, also > with a timeout. > > Note that the test's goal isn't to validate the LPI timer value itself, > only that we enter/leave LPI mode. > > Fixes: 091810dbded9 ("net: stmmac: Introduce selftests support") > Signed-off-by: Maxime Chevallier > --- > [...] > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c > b/drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c > [...] > > + max_duration = usecs_to_jiffies(2 * priv->tx_lpi_timer); tx_lpi_timer comes direct from ethtool as an unvalidated u32. So if a (arguable privileged user) does 'ethtool --set-eee eth0 tx-lpi-timer 1000000000', the code will sleep ~2000 seconds under rtnl_lock. Tge old code capped it at 900 ms regardless of the timer. Thus I think we should clamp it at some sane value. Feel free to keep my R-b with the clamp. > [...] Regards, Nicolai