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 368783655EA; Tue, 14 Jul 2026 12:50:16 +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=1784033418; cv=none; b=EGaFPrwzhWy+JUtx34JQwVkvbYuehg2hN8NEJqIuWxv5/0wicjtw5FGpm2SrVe1xWMDs97H3pLGWAqEWexAzJ7THM95V9Ywzt2yhcw9GAqKj6lVh4UAzWHiLrcr7okczR8KCnN/ZM0DXG8X/9wq1OmzNUfff+KIOIxEaaIH82Oc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784033418; c=relaxed/simple; bh=PqG7oS3Z/lV6BaYYg8l7cJd+xyFoKnA7xPcaifwbyKI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=a5o8CtZknY7skZuEei8O59PhRWBjenWmFHyyi5TqEFtwo6SoNJPvj4ssG/c61F+gKWWFeS8poebYw51rQAj73BzKhWRG+1LJBv3oguFHleqbjkG0HGe9PbwAMv6WKq4pgZiIlU2IJ00wOQJwL2nrAs4W+B1z4vrRhYylINVJPQg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YlU+5xTh; 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="YlU+5xTh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B84771F000E9; Tue, 14 Jul 2026 12:50:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784033416; bh=8mH0j9ii9oCrYiLOBac28i1RSeNAyFN6+6Ihbf0VC8M=; h=From:To:Cc:Subject:Date; b=YlU+5xThoIRK+XjhKF0UUDOeiSkO8wvGChH0uj3Jx9x1laPsu3jJ4bu65WNukqtCe ZGpXFaEBvdiZRtInlqg9FTqx2bAvi2majmn6l0Cj9c+gZDTqqJVJ/RJz9ZLDvJOhkT CWPUBhrsOZdOlbvBQJW9DWNnR1l6cPZ0SlWU0d8K4z+qmWS6lPNH538+1WAgrsoARU 1DZn1gn464fbu2biYUHYkhkW2fO3Jxd6b5AW5UioF/uzbHirKdzTZ8sRL+JDb2SaeV BOXmZkg81Yoz3MbfYxJJRMzEqWXdafj1GXRvtD/STYjyzHWFBiA1hnaMT0erVaHnG7 70KxCO1ebZJQg== From: Michael Walle To: Russell King , Andrew Lunn , Heiner Kallweit , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Michael Walle Subject: [PATCH RFC net-next] net: phy: sfp: drop 1000Base-T support for FCLF8521P2BTL Date: Tue, 14 Jul 2026 14:49:34 +0200 Message-ID: <20260714125008.2466023-1-mwalle@kernel.org> X-Mailer: git-send-email 2.47.3 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The FCLF8521P2BTL is marketed as a drop in replacement for fiber modules using 1000Base-X autoneg towards the host as default. See the referenced application note, esp. question #11. Drop the 1000baseT capability, so 1000Base-X will eventually be used. This is esp. important if the TX_DISABLE pin is not connected on a board. Usually, pin is used as a reset line to the PHY on the copper SFP. If a bootloader expects the default mode and doesn't do any reconfiguration of the SFP module, a link might not be established. Link: https://www.coherent.com/resources/application-note/networking/1000base-t-sfp-faq-an-2036.pdf Signed-off-by: Michael Walle --- I'm not sure, this is the correct place for the fix, nor if it goes in the right direction. There is a comment in /* * Clause 22 copper SFP modules normally operate in Cisco SGMII mode with * negotiation enabled, but some may be in 1000base-X - which is for the * PHY driver to determine. */ I haven't found any traces of that though. So any pointers, what flags have to be modified is appreciated (phydev->supported? phydev->possible_interfaces?). I also compared the EEPROMs of both a FCLF-8520-3 and a FCLF-8521-3 (I don't have a FCLF8520P2BTL) and they are the same except for the P/N and the serial number. So they both advertise the same capabilites. Although I'd suspect that the power-on strapping is different and could be read by the PHY driver. --- drivers/net/phy/sfp.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index b9d84612ac6f..387753cb5c62 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -478,6 +478,16 @@ static void sfp_quirk_2500basex(const struct sfp_eeprom_id *id, __set_bit(PHY_INTERFACE_MODE_2500BASEX, caps->interfaces); } +static void sfp_quirk_no_sgmii(const struct sfp_eeprom_id *id, + struct sfp_module_caps *caps) +{ + linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Half_BIT, + caps->link_modes); + linkmode_clear_bit(ETHTOOL_LINK_MODE_1000baseT_Full_BIT, + caps->link_modes); + __clear_bit(PHY_INTERFACE_MODE_SGMII, caps->interfaces); +} + static void sfp_quirk_disable_autoneg(const struct sfp_eeprom_id *id, struct sfp_module_caps *caps) { @@ -539,6 +549,10 @@ static const struct sfp_quirk sfp_quirks[] = { // PHY. SFP_QUIRK_F("FS", "SFP-10G-T", sfp_fixup_fs_10gt), + // These are sold as 1000base-X compatible. Thus, make sure we don't + // use SGMII. + SFP_QUIRK_S("FINISAR CORP.", "FCLF8521P2BTL", sfp_quirk_no_sgmii), + // Fiberstore SFP-2.5G-T and SFP-10GM-T uses Rollball protocol to talk // to the PHY and needs 4 sec wait before probing the PHY. SFP_QUIRK_F("FS", "SFP-2.5G-T", sfp_fixup_rollball_wait4s), -- 2.47.3