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 4206D40B107 for ; Thu, 20 Aug 2026 19:56:48 +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=1787255809; cv=none; b=P5fD0iZMVQHy0X4FLBRbDzB52BYwyKiBsbiil1wU9SblCBb41Aq14woeJrFn6hFcV6Rn9VfVZ3swp5dceHEp42Zx6BnI6ic3WVLCP1o1o46qhgch3RUj0Un1G6Eg5h/YW99rasGO7CrAc7C5SfXNC6mKmh08qW3EAKhVpk/hclY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787255809; c=relaxed/simple; bh=RmBGPPmnHZB7sWOryRhUyWXwDesZ2C671GMYTmf7+wE=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=PQO4H2i3XmwNXR1bStpHhPaH1xYjNRpnCglvUNZPptBVV/JBg+StoyCLLLPdJnnFfZK/9Z/AtarvDzRwRVifBw6b1FmYj5itzvmXe9+dQtNV5Sesu/fiSvf4hyM4aFjSnkz72tvWU2IlotKVtrofOMJK18ulrmFlPW+Get9h34Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=o1YuBaRD; 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="o1YuBaRD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BDC71F00A3A; Thu, 20 Aug 2026 19:56:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787255808; bh=RmBGPPmnHZB7sWOryRhUyWXwDesZ2C671GMYTmf7+wE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=o1YuBaRDVWZeY84KMiDmiPzm5KnoHfURg7E5uRv2vIDKWk3/BM/u8v6jKfbG446TP IX7mFDZbY+dBYX4d/LafLk2oxK7M3/kqQW9tQ3AZH7wpvq3pG1QCCB+8dqiu95j9vd 0SpUUEIilWG7maQOc2MRUxt2k6Bmliym32UIWLod1H9Utloc6ZoImmpDW9U5khIggG A2Pvvo4hD+5sv6xyd7Y8p8AHKAUWh+tQjqx2DATMqtmEsPp4/q16Insx+1G96kou2d AZ+QwQJ1YTfgL3vwrX4TtPdjcanXiw1uOUcbOsVf4icCLalwYGL45CSALbO2FEBOH6 xPz1+hmUyFkVA== 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: <20260820195334.275375-1-ferran.duarri@me.com> References: <20260820184228.166566-1-ferran.duarri@me.com> <20260820195334.275375-1-ferran.duarri@me.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Thu, 20 Aug 2026 19:56:47 +0000 Message-Id: <20260820195648.0BDC71F00A3A@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/20260820195334.2753= 75-1-ferran.duarri@me.com?part=3D1