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From: Louis Kotze <loukot@gmail.com>
To: Ping-Ke Shih <pkshih@realtek.com>
Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org,
	rtl8821cerfe2@gmail.com, Louis Kotze <loukot@gmail.com>
Subject: Re: [PATCH 2/2] wifi: rtw89: phy: make RF calibration timeouts non-fatal on USB
Date: Wed, 15 Apr 2026 13:13:39 +0200	[thread overview]
Message-ID: <20260415111339.453602-3-loukot@gmail.com> (raw)
In-Reply-To: <9f43a228419b44b1a55ee3d8c31abcbd@realtek.com>

On Tue, 14 Apr 2026 06:39 +0000, Ping-Ke Shih wrote:
> If calibration timeouts, the performance might be bad. How about just
> to enlarge timeout time in 1/2 patch?
> [...]
> It seems like we don't actually handle the return code for now.
> Could you point out the path you encountered?

You're right on both points — dropping this patch in v2.

On the return code: it is indeed discarded by all 8922a callers of
rtw89_phy_rfk_*_and_wait() (11 call sites). My original "connection
failure" report was the host dropping the link after repeated
"failed to wait RF DACK" kernel warnings, not a return-code cascade.
The 4x multiplier in 1/2 already fixes the observable symptom.

Also, on 8922d rtw8922d_rfk_tssi() does check the return and uses
the failure to fall back by clearing is_tssi_mode — making the call
non-fatal on USB would silently break that fallback. Not something
I should ship, even for hardware I don't own.

On enlarging 1/2 only: re-verified the 4x multiplier under stress-ng
(CPU, memory, combined). DACK peaks at 71ms on 5GHz in every
scenario, including baseline idle — the calibrations are I/O bound
on the USB H2C/C2H round-trip, not CPU/memory bound, so host stress
doesn't move the numbers. 4x leaves ~3.3x headroom on the worst case.
Full matrix is in the v2 1/2 commit message.

v2 keeps only 1/2, with the comment-style fix. Sending shortly.

Louis

  reply	other threads:[~2026-04-15 11:13 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <795a8567fdbe48babc5cf0f2b5e10c0a@realtek.com>
2026-04-10  8:00 ` [PATCH 0/2] wifi: rtw89: fix RF calibration for USB transport Louis Kotze
2026-04-10  8:00   ` [PATCH 1/2] wifi: rtw89: phy: increase RF calibration timeouts " Louis Kotze
2026-04-14  6:32     ` Ping-Ke Shih
2026-04-15 11:13       ` Louis Kotze
2026-04-10  8:00   ` [PATCH 2/2] wifi: rtw89: phy: make RF calibration timeouts non-fatal on USB Louis Kotze
2026-04-14  6:39     ` Ping-Ke Shih
2026-04-15 11:13       ` Louis Kotze [this message]
2026-04-15 11:13   ` [PATCH v2] wifi: rtw89: phy: increase RF calibration timeouts for USB transport Louis Kotze
2026-04-16  1:15     ` Ping-Ke Shih
2026-04-16  4:56       ` Louis Kotze

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