From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 BFB0B2D97BA for ; Thu, 20 Aug 2026 20:06:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787256409; cv=none; b=YLKuI4WOD8B8wqKwwk89+YUcIuAg1fESzZpYeaWAtpnKdlKjG9dlqBEfUVqvW7EKBrgH1N9WOOcwwxYrhUUpN7xyFcexZ72MVZTVcEepp9Nsb/InK3jieJ2ECu18UkUEh6XwGQggnf1RuoCQtPuFADkyAP6X/ReCOInjYmEMKJo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787256409; c=relaxed/simple; bh=YCSK7nulFNTRGounBVcKOHtr2x1AlTlaFwEs4XpaCDs=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=dgEG7gn5SwkD+uPZwC0wk92dIWHJl0p46OR9l8b882uwfyBc9Gj/ZVKZY7amWnrXHBHiz+oVh4yat94/eoYiEDCSLhGXSFyVjPg2rxm0nxIVmzWRdiVoBWOgsHf8o29Xs5ZDXM8zQy1Op9XN3t3fVjb0ygjxslYQd+i64MPSilU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=XnUVtc1Q; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="XnUVtc1Q" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 200BB1F000E9; Thu, 20 Aug 2026 20:06:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787256408; bh=YCSK7nulFNTRGounBVcKOHtr2x1AlTlaFwEs4XpaCDs=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=XnUVtc1QdVQRuLXJnKFXCvvZyAm6xX+10Wf6Kui0jbJZ8VUsg+tyE1fA8GHMS66tD dMG3+xXqWBsz0ReDeIJOKeJhJ2a9A8CoJEQlFOnPO3DEnY60Qb+uDhjYfQAPru/1oW xrCNMST8UmxvHYoH9wzNd4IBaRrRcDPLMWvZ90qdiP2UUw8pKWjtMm9/QqM4IoysOL gDdKyzNdft+Rpj/uTrcPZvkaG5sXpz7Xi3d9N9DfnDVRPfiOKre/jxD3u5tTmOK5c6 thoTbx1Ap0vFuCWtg2qLIZcTNjMPBCF1ZM+We7+N1E0xpN2o20FQm865BHzG5Fyhsy CbVzU9ShCRZ7g== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2] PCI/sysfs: document the link speed and width attributes Reply-To: sashiko-reviews@lists.linux.dev To: "Ferran Duarri" Cc: linux-pci@vger.kernel.org In-Reply-To: <20260820200359.283335-1-ferran.duarri@me.com> References: <20260820184228.166566-1-ferran.duarri@me.com> <20260820200359.283335-1-ferran.duarri@me.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 20 Aug 2026 20:06:47 +0000 Message-Id: <20260820200648.200BB1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > max_link_speed, max_link_width, current_link_speed and current_link_width > have been exported under /sys/bus/pci/devices/.../ since 2018, by > commit 56c1af4606f0 ("PCI: Add sysfs max_link_speed/width, current_link_s= peed/width, etc"), > and none of the four appear anywhere in Documentation/ABI. >=20 > The gap matters most for current_link_speed. current_link_speed_show() > performs a fresh PCI_EXP_LNKSTA read on every open, so the value reflects > the link state at that instant. Modern GPUs retrain their link continuous= ly > as part of idle power management, which means a single read can legitimat= ely > return any speed the link supports, not the speed the link will use under > load. >=20 > Observed on an RTX 5070 in a PCIe 4.0 x16 slot, same boot, no configurati= on > change between the two reads: 5.0 GT/s while idle, 16.0 GT/s under load. > Comparing current_link_speed against max_link_speed at idle is therefore = not > [ ... ] > end's capability rather than the link's. >=20 > No functional change. >=20 > Signed-off-by: Ferran Duarri Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260820200359.2833= 35-1-ferran.duarri@me.com?part=3D1