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 C59FD3F1ABE; Mon, 17 Aug 2026 14:26:39 +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=1786976801; cv=none; b=ZECiacgeh0R/lCzwYbiDmKdIlz0YgJXz8VEZgb1BpOV7AgxHzKoVf7HLjtl1P8PVRhixlCDiUlwFH9gB+4otzrADcawGjzk9pnYvAxnA4NQ/InRYeW3ycUqqVdvdVlveXKJq8dwO5jdop2TL8/AjF3g9XMkHBjHRBQN5srA2wUI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786976801; c=relaxed/simple; bh=9ALhicD3vO97VKd2hMZFlTGaNTztLDAA9qYt8iq0JXo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Sue2mg8oOzG/Pg8+g4rZJbVmIbzF73UXnli2k7LvMd5YV/HfEcVcRBvjTATX2FeMqadgZqw1zTbrYXrUPInbKs2Xipq5KtdxubtRfprwp8c8fgPN6yTLrt86vJKylKhotzaExbhybsLs8gtblhH2P0Baudp98XRoRyyCh3/JjBc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=hL0TMW4n; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="hL0TMW4n" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E52BB1F000E9; Mon, 17 Aug 2026 14:26:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786976799; bh=b3bF6jR1niKwNI0INst46wugZf1CDYFLfJJCV0D3jv4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=hL0TMW4nEsGXriev1mvDrwMODZFbirO6249hmNQXAD0w/lkvGWezIwzQ1m6cPcpnN llnWvBjHuCt1c0dRtACOBgATAO4cNowEp1D+X05A9HBWIMvVNHjhMvjMVAyI3dBgix i8z6xHqvS0DW/OWCmB+TiK4EdOBv/Qwv7vKIgAyA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Patrick Oppenlander , Prashanth Kumar KR , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 109/456] amd-xgbe: fix MAC_AUTO_SW handling in CL37 AN Date: Mon, 17 Aug 2026 15:28:19 +0200 Message-ID: <20260817132544.354533776@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Prashanth Kumar KR [ Upstream commit 4bf22afe53a1de4b44b04cf677fd5199089cbdff ] MAC_AUTO_SW (VR_MII_DIG_CTRL1 bit 9) enables automatic XPCS speed mode switching after CL37 auto-negotiation and is only meaningful in SGMII MAC mode. The original code unconditionally set this bit on every call to xgbe_an37_set(), including when called from xgbe_an37_disable() with enable=false. This left MAC_AUTO_SW=1 after AN was disabled, causing the XPCS to autonomously switch speed from stale AN state during subsequent mode changes, breaking SGMII speed negotiation on 1G copper SFP modules. Patrick: This was breaking negotiation for all 1G SFP modules, not just copper modules. Fixes: 42fd432fe6d3 ("amd-xgbe: align CL37 AN sequence as per databook") Reported-by: Patrick Oppenlander Link: https://lore.kernel.org/netdev/CAEg67GmFS0Q4oSZkz8zWdOzckSth9_vBPiOy6a7-d697C2w2Xg@mail.gmail.com Signed-off-by: Prashanth Kumar KR Tested-by: Patrick Oppenlander Link: https://patch.msgid.link/20260709095006.3683940-1-prashanthkumar.k.r@amd.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- drivers/net/ethernet/amd/xgbe/xgbe-mdio.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c index ebb8b3e5b9a882..01c37ffc9ceb81 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-mdio.c @@ -364,9 +364,14 @@ static void xgbe_an37_set(struct xgbe_prv_data *pdata, bool enable, XMDIO_WRITE(pdata, MDIO_MMD_VEND2, MDIO_CTRL1, reg); - reg = XMDIO_READ(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL); - reg |= XGBE_VEND2_MAC_AUTO_SW; - XMDIO_WRITE(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL, reg); + if (pdata->an_mode == XGBE_AN_MODE_CL37_SGMII) { + reg = XMDIO_READ(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL); + if (enable) + reg |= XGBE_VEND2_MAC_AUTO_SW; + else + reg &= ~XGBE_VEND2_MAC_AUTO_SW; + XMDIO_WRITE(pdata, MDIO_MMD_VEND2, MDIO_PCS_DIG_CTRL, reg); + } } static void xgbe_an37_restart(struct xgbe_prv_data *pdata) -- 2.53.0