Re: [PATCH] wifi: rtw88: 8821c: Add HP single-antenna quirk

[Paolo Lazzaroni <eexto@aol.com>]

On Sun, Sep 13, 2026 at 02:15 UTC, Ping-Ke Shih <pkshih@realtek.com> wrote:
> Should use your full real name.
> 
> You sent the same patch by different mail address. I'll drop previous one.

Both patch submissions were identical, but please ignore the submission from
p17232763@gmail.com. I will use this address (eexto@aol.com) with my full
legal name (Paolo Lazzaroni) for all future submissions and v2.

> I don't see rtw88 has ' rfe_option_full' ?

Apologies, the previous patch was based on an out-of-tree backport tree.
I have checked out rtw-next where rfe_option_full does not exist, and will
only set efuse->rfe_option in v2.

> If this is the only one platform which needs this kind of quirk. Add an entry
> to rtw_pci_quirks[].

Regarding rtw_pci_quirks[]:

The reason I matched the PCI subsystem ID (10ec:c821 [103c:831a]) rather
than DMI in rtw_pci_quirks[] is that HP assigns this specific subsystem
ID across a family of laptop platforms (e.g. HP 15-da, 15-db, and related
chassis) to denote the single physical antenna connected to Aux/S1.
This is documented in the OEM Windows driver INF (netrtwlane.inf):
  "PCI\VEN_10EC&DEV_C821&SUBSYS_831A103C ;;single ant(connect to right one S1)"

If we use DMI matching in rtw_pci_quirks[], it would only match this specific
laptop SKU ("HP Laptop 15-da0xxx" / "4XW76EA#ABZ"), leaving other HP models
sharing this identical 103c:831a single-antenna card with severe signal loss.

However, I understand that inspecting PCI structures inside rtw8821c_read_efuse()
violates bus abstraction for rtw8821c.c.

Would you prefer:
Option A: Keep the PCI subsystem match, but handle it cleanly in rtw_pci_probe()
          (e.g., setting a flag or rfe_option override in rtwdev before chip setup)?
Option B: Add a DMI entry to rtw_pci_quirks[] matching this platform?