From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 71211C46470 for ; Wed, 8 Aug 2018 11:38:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 214D32083D for ; Wed, 8 Aug 2018 11:38:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=kapsi.fi header.i=@kapsi.fi header.b="p/Bw2F6N" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 214D32083D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kapsi.fi Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727048AbeHHN5x (ORCPT ); Wed, 8 Aug 2018 09:57:53 -0400 Received: from mail.kapsi.fi ([91.232.154.25]:40555 "EHLO mail.kapsi.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726733AbeHHN5x (ORCPT ); Wed, 8 Aug 2018 09:57:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=kapsi.fi; s=20161220; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:References:Cc:To:From:Subject:Sender:Reply-To: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=Cv+Tn3WHkfXrn/SQlAhjidlfalrP8jIrTTc8zGGVA4A=; b=p/Bw2F6NA/pHOA5A9rH/SYvz0d 995FGin0KTgpeHt83oOEho9lQLtsMI4BGDjYNnYu7eFyNGBxAxlKWPkZqyU4KvzeGuDgNpXZbpn6P Yl06P+BzPiYHimX4ReAM3rTpbOkZVP8Ar8g6Y7D/vTtWP0QQX3RYb4o8uylyost7ZG1YU612O2Zx6 7v1aYUCCGmLT3QTZFF7ahwcOSvSszXTeOSjTK+i1NU6nci8+09g0FzYxo5ZUuGAfrfX2BeZ5hfYzd tFE4BlEjZz1wulkyIIZxuQmChDLXfYTuh72XH0lAmv2IwkjQW976HMKd/k1+tDqPEWrhdQIUKpvYT Nn/N5+hw==; Received: from [193.209.96.43] (helo=[10.21.26.144]) by mail.kapsi.fi with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.89) (envelope-from ) id 1fnMnM-0004h8-BC; Wed, 08 Aug 2018 14:38:28 +0300 Subject: Re: [PATCH v3 3/8] mailbox: Add transmit done by blocking option From: Mikko Perttunen To: Jassi Brar , Mikko Perttunen Cc: Greg KH , Thierry Reding , Jon Hunter , Devicetree List , linux-serial@vger.kernel.org, linux-tegra@vger.kernel.org, ", linux-arm-kernel"@lists.infradead.org, linux-mediatek@lists.infradead.org, srv_heupstream , Linux Kernel Mailing List References: <20180702114033.15654-1-mperttunen@nvidia.com> <20180702114033.15654-4-mperttunen@nvidia.com> <907bac36-0c54-8f38-0f5e-f59196d414c6@kapsi.fi> Message-ID: Date: Wed, 8 Aug 2018 14:38:28 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <907bac36-0c54-8f38-0f5e-f59196d414c6@kapsi.fi> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 193.209.96.43 X-SA-Exim-Mail-From: cyndis@kapsi.fi X-SA-Exim-Scanned: No (on mail.kapsi.fi); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04.08.2018 13:45, Mikko Perttunen wrote: > On 08/03/2018 03:54 PM, Jassi Brar wrote: >> On Mon, Jul 2, 2018 at 5:10 PM, Mikko Perttunen >> wrote: >>> Add a new TXDONE option, TXDONE_BY_BLOCK. With this option, the >>> send_data function of the mailbox driver is expected to block until >>> the message has been sent. The new option is used with the Tegra >>> Combined UART driver to minimize unnecessary overhead when transmitting >>> data. >>> >> 1) TXDONE_BY_BLOCK flag :- >>          Have you tried setting the flag >> mbox_chan->mbox_client->tx_block ? > > No - I suppose I should have done that. I'm a bit concerned about > overhead as send_data may be called thousands of times per second, so I > tried to make it as close as possible to the downstream driver that just > pokes the mailbox register directly. I tried using polling in the mailbox framework. Some printing is done from atomic context so it seems tx_block cannot be used - wait_for_completion_timeout understandably does not work in atomic context. I also tried without tx_block, in which case I got some horribly garbled output, but "Try increasing MBOX_TX_QUEUE_LEN" was readable there. Any opinions? Thanks, Mikko > >> >> 2) Implementing TEGRA_HSP_MBOX_TYPE_SM :- >>         In mailbox framework, a controller is a collection of identical >> channels. That is, instances of the same class. >>         So ideally, in probe you should populate a controller for each >> type of channel, i.e, DB, SM, SS and AS. > > Hmm, yes, I guess this would be possible if I change the mailbox core to > allow registering multiple controllers per device. > > Thanks! > Mikko > >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-tegra" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at  http://vger.kernel.org/majordomo-info.html >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-tegra" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at  http://vger.kernel.org/majordomo-info.html