From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 88C05606A327 for ; Thu, 12 Nov 2026 13:52:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=ZKzxvIfN; dkim=pass (2048-bit key) header.d=thregr.org header.i=@thregr.org header.a=rsa-sha256 header.s=v1 header.b=t6MT0ktN DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Unsubscribe-Post:List-Owner; bh=FQEToc/tllkwE/usKVnhOlAx/N0Rs4tX+3kATA9NrBg=; b=ZKzxvIfNJtdIKlekxoDxTfR1df 2p1BQYBWGlxpz51TTszdyj6OSfNnwqwrE/wntqsrdrsfpkcEOn/+UE7aQsT6addAZ6R+iKXondSla fXIxu/RRanmS/8h5pQpGSEGFff0FJejDXvXVajpDFCnMSawdfyJbThFM65AaQu/sT5dHbJ3nfUFAM FHCvVKoShqUbcjpTXXF7/6oXkeER8PPUxEz2JCYH2PsJWFFYMRAiSPQj1TAWMsBLxyK9X1GVIKo0k Kdp5ZUaxG2PD7rvs/Gv6S5QqSM2/0qyrSQ2B23ok4i6eVBShZBy34232UvrrKfiLdotYwtPrSLZsP MO4lj3zg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xRVE9-0000000A9Ik-0J0I; Thu, 12 Nov 2026 13:52:33 +0000 Received: from erc.corrupted.graphics ([2a0d:f302:114:5502::1]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xRVE4-0000000A9GU-3E6U for linux-mediatek@lists.infradead.org; Thu, 12 Nov 2026 13:52:29 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=thregr.org; s=v1; h=Content-Type:MIME-Version:Message-ID:Date:Subject:Cc:To:From:Reply-To :Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: In-Reply-To:References; bh=FQEToc/tllkwE/usKVnhOlAx/N0Rs4tX+3kATA9NrBg=; b=t6 MT0ktNgsaefXAJFNNX6ger94HQZcOCpKz+2oDCmjK3qvopSRlTJJtJkfTVoI6q7oLWMso+jZJEMRm EjfUUyKzgaErZSoqvXMHD1qScHYjKy8B+T+OqCMIS1MkOyi/K5dMmy57D+VHiOJE+YmWOFKQ4HLhA /ED7BMUUgAXk7jSuGk/ZkGx2dT8Fd3KzXTByOD9nDNboaJw2exmU24sSU+jbEPa/a8XUsY49mb2uy yXCLG8l7W/am9ikyQ6v93DlkeU+A8mcWfbMxIAY1J/OomNSML7ps6nPXND9z2TWIoPk/wGpFenq3N chZMijAxPqsHaxQHZa5ywZiKGWRAe4TA==; Received: from 78-213-86-123.subs.proxad.net ([78.213.86.123] helo=localhost) by erc.corrupted.graphics with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256:SECP256R1) id 1xRVE7-00000000ASv-2SOc (envelope-from ); Thu, 12 Nov 2026 14:52:31 +0100 From: Yuri D'Elia To: linux-wireless@vger.kernel.org Cc: Felix Fietkau , Lorenzo Bianconi , Ryder Lee , Shayne Chen , Sean Wang , JB Tsai , Charlie-cy Wu , linux-mediatek@lists.infradead.org Subject: mt7925e: TX throughput collapses without RX traffic User-Agent: mu4e 1.14.5-pre1; emacs 32.0.50 Date: Thu, 12 Nov 2026 14:52:26 +0100 Message-ID: <871p8q2m3p.fsf@wavexx.thregr.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20261112_055228_808877_F59DF48E X-CRM114-Status: UNSURE ( 8.51 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -2.1 (--) X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-mediatek" X-Spam-Status: No, score=-5.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 Hi, I'm using an ASUS ProArt PX13 with an MT7925 that performs randomly. Sometimes it has decent throughput, sometimes drops to a crawl. TX throughput collapses whenever the host is not also receiving traffic. RX is fine. I'm on 2.4 GHz 802.11n/HT 20 MHz, MCS7 both ways. The peer I'm testing against is another client on the same AP. I did a UDP test with 1200 byte packets, sending at 5 to 40 Mbit/s: MT7925 -> peer: 0.6-1.0 Mbit/s received at any sending rate, 1-2 s queueing MT7925 -> peer, while peer sends ~200 pkt/s to MT7925: 5.0-5.8 Mbit/s received, ~0.13 s queueing peer -> MT7925: all received up to ~20 Mbit/s, no loss Same result on: - kernels 6.18.62, 7.3.3, 7.4-rc1 - MT firmware 20260605184805, 20260813113118, 20261016233029 The following had no effect: - ASPM L1/L1.1/L1.2 off, runtime-pm and deep-sleep off, power_save off - AQL off - TX A-MPDU sessions kept stopped - IOMMU group switched to identity - Bluetooth rfkill-blocked What I see in the driver: - Without RX traffic, frames go out in bursts of ~48 (the UDP socket buffer), then nothing until the next TX-free report, up to ~1 s. - I sampled WFDMA registers through regidx/regval during a stall (~7 samples/s, ~20 s): RX ring 2 DMA index always matches the driver tail within one sample, the RX data interrupt was always enabled, and HOST_INT_STA has nothing pending. Ring 2 advances by only ~13 entries while ~1180 frames were sent. - Wi-Fi IRQs: ~2.6/s idle, ~82/s during the stall. So the driver processes ring 2 quickly. The firmware seems to write TXRX_NOTIFY only about once per second when there is no RX traffic, and sooner when RX traffic arrives, which would explain the seemingly "random" performance. There are several reports of poor MT7925 throughput on linux-wireless, the kernel bugzilla and the openwrt/mt76 tracker, but I didn't find any that points to this. Is there a firmware setting for the TX-free report interval or threshold that mt7925 should send at init? I can test patches and provide more data. Thanks