From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BF6F2475D0 for ; Fri, 22 May 2026 06:49:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779432548; cv=none; b=T54ayunyif3BV0eDe8HZgDtQLWmrX9PMpZNMcWEaPijMFAY7al63x2A0+7jhta9Zrxsm3CTsHcbbIqRAbQrl+rTkQSel/EfnPwTIN50MzIdyxI/yd/mgSrRgb+o9bgzdzhfzASRWmrfLSPS29/OSEiCYM49uksIxQgkBtmGJfyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779432548; c=relaxed/simple; bh=BCaBxs0ytwR14idu/LE2WlR87+13hVDE/LzvxugRAhc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=LPlqlUoPo4VusEYrw75TBQvYHYugm/FmKj7OQvD7SE3B1fKKtv6kYnF0KkgZHwID+ODnLg4YmG5LgLBH4QweGqmpojzoPVZO6hVg1EALuo1BAOoCBW4ekefgq4bLi4iMXPlbOEMUkKEXANVwblwub+baPJtK9qEQDzC9FA7vOHk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YqaLTmFH; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YqaLTmFH" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1779432546; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=08GD5FnVc7SUxNkQ3OeIOdIy8gx67eouJZS3Q8GyD8c=; b=YqaLTmFHLHJ89QN7KfDVklyUQU2XvE8FAIbjn9Lqi6PTKBVx/NMLPGbcm7csMxtKowrrJ7 /8TUdLfwbiTUfALOIEZiiIGe+fm9T3s8zMzuw6y4Fu/OpvAPRe4y+LMr6ki9cMrfQWSYlm zBQhB8ne9Hh5rs7nOQgouJ29zP9f4MY= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-97-AanC6XFBOoWUpB6lctE_Xg-1; Fri, 22 May 2026 02:49:03 -0400 X-MC-Unique: AanC6XFBOoWUpB6lctE_Xg-1 X-Mimecast-MFC-AGG-ID: AanC6XFBOoWUpB6lctE_Xg_1779432541 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 9F2C61956094; Fri, 22 May 2026 06:49:00 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.44.32.37]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 055C21800352; Fri, 22 May 2026 06:48:55 +0000 (UTC) From: Jose Ignacio Tornos Martinez To: helgaas@kernel.org Cc: Ryder.Lee@mediatek.com, alex@shazbot.org, bhelgaas@google.com, jtornosm@redhat.com, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-wireless@vger.kernel.org, lorenzo@kernel.org, nbd@nbd.name, sean.wang@mediatek.com, shayne.chen@mediatek.com Subject: Re: [PATCH v3] PCI: Disable broken FLR on MediaTek MT7925 Date: Fri, 22 May 2026 08:48:53 +0200 Message-ID: <20260522064854.201976-1-jtornosm@redhat.com> In-Reply-To: <20260521161932.GA167656@bhelgaas> References: <20260521161932.GA167656@bhelgaas> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 Hello Bjorn, Thank you for the feedback. > How do we know the device is an "undefined state"? Does it just not > respond to config accesses? Is there something in dmesg that shows > the problem? > I suppose it's similar to 81f64e925c29 ("PCI: Avoid FLR for Mediatek > MT7922 WiFi")? > I guess I'm just looking for some text more specific than "undefined > state". You're right, "undefined state" is too vague. I can prepare v4 with what I've seen is happening . The symptoms are similar to MT7922 but not identical: **First VM start (works fine):** mt7925e 0000:08:00.0: ASIC revision: 79250000 mt7925e 0000:08:00.0: WM Firmware Version: ____000000, Build Time: 20260106153120 **After force reset/VM crash (FLR attempted, firmware communication broken):** mt7925e 0000:08:00.0: ASIC revision: 79250000 mt7925e 0000:08:00.0: Message 00000010 (seq 1) timeout mt7925e 0000:08:00.0: Failed to get patch semaphore (Repeats 10 times with increasing seq numbers) mt7925e 0000:08:00.0: hardware init failed Unlike MT7922 which shows config read failures, MT7925e config reads work correctly after FLR (lspci shows all capabilities). However, firmware communication is broken - the driver cannot acquire the patch semaphore needed for firmware initialization. The device remains broken until physical power cycle. Secondary Bus Reset (fallback after quirk_no_flr) successfully resets the device and allows reinitialization. > Can we get any of the MediaTek folks to comment on this: > https://sashiko.dev/#/patchset/20260508145153.717641-1-jtornosm@redhat.com?part=1 > > Sashiko suggested that Device ID 0x0717 might have the same FLR > problem. I don't have that device to confirm the same behavior. I'll wait for MediaTek maintainers (now CC'd) to confirm whether 0x0717 exhibits the same FLR issue. If confirmed, I can add it in a follow-up patch or the next version. Thanks Best regards José Ignacio