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 AF7F24A0EF7 for ; Tue, 6 Oct 2026 16:24:32 +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=1791303877; cv=none; b=FyQv1mcfTNUu6DdX0guQY3BftKv24iLeIYl/ZH4ojU32yYAFyvcbssFWUUDXuWC6i9FhDfvk9G95AVe6+iGTD3r4Hr2A3167QTlZvR5kr6TiIPVGp7vRtkQJhkzatGxdqzGNTOpFAI5fKB7Vjkr4oYNL3PCBxdE0TWcytOU5S2w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791303877; c=relaxed/simple; bh=zWrZH8Mk9ZNTVgL04kDn0HKKpXTxoYtRqR3zwOaEQug=; h=Message-ID:From:Subject:To:Cc:In-Reply-To:References:Content-Type: Date; b=SZBEnaflmR8i5S0r0Ma3Llg3BYbCk5oTjVGgSZw+Pp1xCPMMgrVsZjpXSZFSbDLlR7rbdcN65CJOc7Do0DRyadzBgYBwHU2eF2811r7VOKgySDkHrYNn+YV6J9PchIFmiozcDUPQ7dHg+sbOcCU7aYt+mG9kEPikDLP91VG3dd4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JwCCSsh8; 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="JwCCSsh8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27C531F0089D; Tue, 6 Oct 2026 16:24:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791303869; bh=2fbebFvR0OdlleOmY2MtR/KbWX0YqItpwFe/EpYMRHI=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=JwCCSsh8Fh6wvatpBOkS2/PDL/Yq5b58C0BhULK35bWxAwxt6M1aJG8Tumz+zd8M3 dKdHcxYkTynXROs08CRddpfURUYgXcZIgtHEgPp7ijlDM7Hn68NIC1z30sVbZ9nfDo HsaQ7ZB7BqJSLqqbHey8VnGp4Isrf+S2yrDiZr5E8na0Vlwxnb4WL3+CxV8C4VqVKw rMYIuA1DOOkcCCEs/t9awzbOteFQuHBgdl4FVko/el9XrmpRMmQ6ej26wMiVoPgESO cBtS3Lg74pqbJRRQQGUGRkNVPjNBILRAwyj6iwik+FUTEQkiH/f3J2N8klZhHfR5Q8 3h6Lp34b3Y4Jg== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v4 1/2] PCI/LMR: Add Lane Margining at the Receiver debugfs interface Reply-To: sashiko-reviews@lists.linux.dev To: "Priyank Rathod" Cc: linux-pci@vger.kernel.org In-Reply-To: <20261006-pcie-link-endpoints-v4-1-ad5398c4260c@google.com> References: <20261006-pcie-link-endpoints-v4-0-ad5398c4260c@google.com> <20261006-pcie-link-endpoints-v4-1-ad5398c4260c@google.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Tue, 06 Oct 2026 16:24:28 +0000 Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: > Lane Margining at the Receiver moves the sampling point of a receiver > away from its normal setting, in time or in voltage, while the link > stays up, and reports the errors the receiver sees. It is available > on links running at 16.0 GT/s or faster, through the Lane Margining at > the Receiver Extended Capability. >=20 > Add a debugfs directory, pcie_lmr_, for each Downstream Port > and each Function 0 below a Downstream Port that has the capability. >=20 > Writing 1 to 'enable' starts a margining session on the link. ASPM is > turned off with pci_disable_link_state(), Hardware Autonomous Width > Disable and Hardware Autonomous Speed Disable are set on both ends, > both ends are kept runtime resumed, and the port's Margining Ready bit > is awaited. Writing 0, or removing either end of the link, ends the > session and undoes these steps. Only one session can be active on a > link. >=20 > During a session, 'receiver' selects the receiver, laneN/margin_timing > and laneN/margin_voltage issue Step Margin commands, laneN/caps shows > the parameters the receiver reports, and laneN/status shows the > response to the last step command, including the error count. Before > each command, the link is checked against the state the session > started in: speed, width, Margining Ready, ASPM still off, and no > system suspend since. >=20 > The kernel does not run margining sweeps or interpret the results; > that is left to user space. >=20 > Signed-off-by: Priyank Rathod Sashiko has reviewed this patch and found no issues. It looks great! --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261006-pcie-link-= endpoints-v4-0-ad5398c4260c@google.com?part=3D1