Re: [PATCH net-next] net: sfp: Add quirk for Dell M14MK module

On Fri, Aug 07, 2026 at 09:30:25PM +0000, Xander Wilmink wrote:

Greetings,

This adds an quirk for the Dell M14MK (S28-10G-25G-SR-85C) SFP28 module.
These are short range fiber modules, and should advertise 10000baseSR/Full.
Incorrectly these advertise as being a copper module: 10000baseCR/Full. 
The link fails to come up, and the kernel logs "unsupported SFP module: 
no common interface modes."
With the quirk added, the 10Gbit/s link comes up.

Tested on a Linksys LGS328PC with OpenWRT SNAPSHOT version:
OpenWrt SNAPSHOT r35298-2a73f02e56 / LuCI Master 26.190.71895~a18dc50.
Ethtool advertises now "10000baseSR/Full" and the link works on 10Gbit/s.

Thank you for your time.

Kind regards,

Xander Wilmink

The commit message should be formal, since it becomes part of the
Linux kernel. Please remove the Greetings, Thanks, Kind regards etc.

+static void sfp_quirk_25g_10g_dual(const struct sfp_eeprom_id *id,
+				   struct sfp_module_caps *caps)
+{
+	linkmode_set_bit(ETHTOOL_LINK_MODE_10000baseSR_Full_BIT,
+			 caps->link_modes);
+	__set_bit(PHY_INTERFACE_MODE_10GBASER, caps->interfaces);

Do you need to clear 10000baseCR/Full here?

Does it get the 25G part correct? The quirk itself is only touching
10G, so the _25g_ in the name seems irrelevant.

    Andrew

---
pw-bot: cr