From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A143E515979 for ; Fri, 18 Sep 2026 16:15:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789748138; cv=none; b=JcDrhJG8WQDCH0tu4d4Ejn8hNOg7t6z6RQBcj6eVd3gTyXQiXwwg1qV2sPSQliKls2Ko2mJDVJ1temuU9OyKdA5xXPr5RGZoqmB87b2sC+qBYgMFQrx/5ZHMZIp124NdXsIpC8RFVnTOdN/OrY+3HtCrZY4eiiuXG7BHOGrFVuc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789748138; c=relaxed/simple; bh=qL2DsK3iIAkxnuzj84HK3kh3SaEQKy0LjipLQU8ZDPE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=KaVQBi+l4QjArJWNPxNXS+No1DBvLpx3ggf8Ddmhm4f7ofG3fWgO0rSjW8sxFbl8jQykrGeXVm6S1GWp21IbSkQK5CJ7GyQjCU75w2qsy1+NFYZ0vvJ312tiv5F/q7w/yU2VAtlGGjI+HjBWPIkWB8wQedyC72OQXfKP6M7yCVs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=UDOQHXfL; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="UDOQHXfL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0704C1F00899; Fri, 18 Sep 2026 16:15:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789748131; bh=Hl/qrTfNVThcHDtkWLidd7kTkVp5iYgAlxNzRrRRJ9s=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=UDOQHXfL28fjer5Mfclv343LKQjOARc0N6PhFsqadOlAKKV63CtepH7EdE7Kpy+vI d2Xc6xQJYC4ilp86rFOTgQbC/JmuUvgvmFJgWyBJkYUceN1w81zfHnvFULDLlnwPnQ D/Cj0oP/4wm4+qB6EpIVUlYgF8zl7lXPxIFrRMBTHfToS85A0usua0EcaBrLq0iOw5 YkgGdeNXvYyJKxxupiBMLTKpBsSEJQ1r5HstMjJZDJKZz3gncTVagF0XcgHv89M24Y ldfUQNRXMYz2qn6CdA4znf9waOgf7ZbVBfoShyRJtRD1YloR/EHMK8YiWfoxysW36T BehML6t7TNaFQ== Date: Fri, 18 Sep 2026 17:15:26 +0100 From: Simon Horman To: Alexander Duyck Cc: netdev@vger.kernel.org, Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , kernel-team@meta.com Subject: Re: [net PATCH v2 5/6] eth: fbnic: Set AW_FLUSH_MODE alongside AW_FLUSH when flushing the mailbox Message-ID: <20260918161526.GU51261@horms.kernel.org> References: <178941996343.7700.9376081102002673062.stgit@ahduyck-xeon-server.home.arpa> <178942022583.7700.11050671998277309744.stgit@ahduyck-xeon-server.home.arpa> 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-Disposition: inline In-Reply-To: <178942022583.7700.11050671998277309744.stgit@ahduyck-xeon-server.home.arpa> On Mon, Sep 14, 2026 at 02:10:25PM -0700, Alexander Duyck wrote: > From: Alexander Duyck > > When tearing down the FW mailbox Rx ring, fbnic_mbx_reset_desc_ring() > writes AW_CFG with FLUSH set and everything else, BME included, cleared. > Clearing BME halts the device's writes to the host but leaves the staged > requests parked in the PUL write pipeline rather than draining them, so > on the write path FLUSH alone never terminates the outstanding requests > and the flush the firmware waits on never completes. > > Add the FLUSH_MODE definition and set both bits so the staged writes > drain out of the pipeline on their own. BME stays cleared, so nothing > lands on the host; it is restored later in fbnic_mbx_init_desc_ring() > when the ring is rebuilt, once the outstanding writes are gone. > > The read path is unaffected. AR_CFG has no equivalent mode bit and > AR_FLUSH terminates the outstanding reads by itself, so it is left as > is. > > Both writes remain plain stores rather than read-modify-writes. That is > deliberate: the matching write in fbnic_mbx_init_desc_ring() restores > BME and the TLP attributes, and clears both flush bits as a side effect. > > Fixes: 3b12f00ddd08 ("fbnic: Gate AXI read/write enabling on FW mailbox") > Signed-off-by: Alexander Duyck Reviewed-by: Simon Horman