From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E4ABA314A70; Thu, 11 Sep 2025 14:55:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757602517; cv=none; b=u7LiNyKpRXY+1zn5ZOC+DPNgPDotZfNv7QAtlkmVsNz3ohDwjKO8zoP3i5c0z/au3DLNBgOPL7U7Uf5rYD8nABncXWs1IkiTfbKNMkhffqdpaSFyxSe0YDa4wAiEEYRIvZp7omGQ4dpILHDiofGzeKihHaPknEz0hF3ZRQ6s+4g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757602517; c=relaxed/simple; bh=U/J1oy0yLzD+5vHPtcYAKVk7rNrPHlE6BjC7Eb+5HLg=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=gUhiq61Dq1cGk3FAlVil0rhFAGF9T+tC1UXxndYsScBEJIidnbxyEm0VmoAQwwsxXBPJ8osjij/hEM600mYuC3K1pEkTr5DvYN8D/HOSZCtpKFQ9I2vVwJHgmGcdounNNB4RUEDbhdNekH/+PvY5QItgSD/HwKLxbDWhxb01Zj0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=liTJD3JT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="liTJD3JT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C5727C4CEF5; Thu, 11 Sep 2025 14:55:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757602514; bh=U/J1oy0yLzD+5vHPtcYAKVk7rNrPHlE6BjC7Eb+5HLg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=liTJD3JTrjya52KE9p4+dsxrdr5hf97KI0Y6+KFqH+EoXBZxPjkpAV3NdwNRhKO2E MkHiynaX0qvy7FWqo0DTvY/L7mxzygfPx1Q3wsFNgiEHBFCYh6YQkZoanzVKlPGnOl X8ZXW9yOGHOcNMHbUbOIM4/fdhvF6PI53CX19BidQPJugFDtQr1LSwvDlXPk1Cc4nj f9c+43B8StFT4NC+4v4Lt770ALmUw40Iw9pXAPAHb/gVGKzjdcRaqEJGwuY/hEkNZ2 pwluOeCoPqYAF2fJso0gk0fsI9u+451NZ0G7Cq6Pc2/HuoBKm0KnZBJYbBpKwiCaG4 3S+sUgP/1VcIg== Date: Thu, 11 Sep 2025 07:55:13 -0700 From: Jakub Kicinski To: "Russell King (Oracle)" Cc: Marek Szyprowski , Oleksij Rempel , Andrew Lunn , "David S. Miller" , Eric Dumazet , Paolo Abeni , Hubert =?UTF-8?B?V2nFm25pZXdza2k=?= , stable@vger.kernel.org, kernel@pengutronix.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Lukas Wunner , Xu Yang , linux-usb@vger.kernel.org Subject: Re: [PATCH net v1 1/1] net: usb: asix: ax88772: drop phylink use in PM to avoid MDIO runtime PM wakeups Message-ID: <20250911075513.1d90f8b0@kernel.org> In-Reply-To: References: <20250908112619.2900723-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Thu, 11 Sep 2025 15:39:20 +0100 Russell King (Oracle) wrote: > I'm not surprised. I'm guessing phylib is using polled mode, and > removing the suspend/resume handling likely means that it's at the > mercy of the timings of the phylib state machine running (which is > what is complaining here) vs the MDIO bus being available for use. > > Given that this happens, I'm convinced that the original patch is > the wrong approach. The driver needs the phylink suspend/resume > calls to shutdown and restart phylib polling, and the resume call > needs to be placed in such a location that the MDIO bus is already > accessible. We keep having issues with rtnl_lock taken from resume. Honestly, I'm not sure anyone has found a good solution, yet. Mostly people just don't implement runtime PM. If we were able to pass optional context to suspend/resume we could implement conditional locking. We'd lose a lot of self-respect but it'd make fixing such bugs easier..