From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=46.102.156.145 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794491549; b=tNShPBDxLrefnUFdYIL8at/tGRK8PGW+WSphEAbtz/CkdeHD/hIlR5qmmm0euoQ33JXk /uQyE5IrwI/v1oRcS2L60ow/1dDMFcYZm5bfQiWZs1P+zFm63XRm8vCNnStUrTkpdqaAM KdaFQ2k9EG+72qGK5b+geMgirjeYJxc8v3muCoKbjHujPXxjgWFh9p2Yz94qKWndiEk0p 50TS+mFUC2jdv69rjwMowlFI1yB3F5Oml3Fcn+dhAYq1YeAAF0Nr45Uxc9YbhUcDePI+P h0roTPcFSGnsNG2xldaUcFjpOtjwWEFYkbJDdmGjWujCTYZ8I02x4KtiHvsgxkELTow== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794491549; h=DMARC-Filter:DKIM-Signature:Received:From:To:Cc:Subject:User-Agent: Date:Message-ID:MIME-Version:Content-Type; bh=FQEToc/tllkwE/usKVnhOlAx/N0Rs4tX+3kATA9NrBg=; b=Ii9WYSXS47fyPGITVb9xk4TZLoGueANj24igXe09WlJE/mTvblFslLIoaTrZP/kpPpwH 26hqpmpuDfc9WET7I+bcwu6KbOzk0AhR0n0EnQMAIBP7O0OpkvOptiWeDX/3hMGDAdsUM YrY7t95UEWpL7v9HFHYfPj2A1agTQQ+7uKH+QdhPbQyF8usL7QVwkRyNyoIruuz+eAEFC 64+fhopbvMVcSqnE8zDfcZVX0znJ8uV1Xp4mh+hdpriMigFypvWQTr44PMDLwE+towBUA 345Go8dMaP0bQQnzngkudZulapV22ECDfUdqb6Hig40zyn9RdOx+jcfXlCnAg9X06Iw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=thregr.org; spf=pass smtp.mailfrom=thregr.org; dkim=pass header.d=thregr.org header.i=@thregr.org header.a=rsa-sha256 header.s=v1 header.b=D4kRu29O; arc=none smtp.remote-ip=46.102.156.145 Received: from erc.corrupted.graphics (erc.corrupted.graphics [46.102.156.145]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (prime256v1) server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 42181606A31C for ; Thu, 12 Nov 2026 13:52:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 42181606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=thregr.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=thregr.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=thregr.org header.i=@thregr.org header.a=rsa-sha256 header.s=v1 header.b=D4kRu29O 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=D4 kRu29O30nTECC5LmTvTWsDx4JUKUycz8dJgYWoujzhtzkwE+ZjdA72hEsh5NOpT4WGKVXbEEvzIOA rU89YQcFSWufak38uTi0NxTCb778gooTUJZxtLytRtXbCYvy+SQJXIaycxv8vQRvzV3HciEqkpPtf euPuo5iH7Mb+u1jX7loAa1gYaO91qBeClx5o7uvJ+5npYZvOQuDtyOqM0JANVRNjA2+WlVG6aCFYt WMhvTQNIrQHgvxVmsiIrPXCkPDKhn6CtV+G9swZLWwsKTwDt+cNRglqUizrGQmDjp7z4oh8xKr+Mb 6Dt/SObMyG8TYLVmdO0kFyzLWSv8EsJg==; 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 1xRVDx-00000000ASf-4B8d (envelope-from ); Thu, 12 Nov 2026 14:52:22 +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 14:52:16 +0100 Message-ID: <874idm2m3z.fsf@wavexx.thregr.org> X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain 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