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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 47491C43331 for ; Wed, 1 Apr 2020 06:28:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 118AC2077D for ; Wed, 1 Apr 2020 06:28:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731813AbgDAG2p (ORCPT ); Wed, 1 Apr 2020 02:28:45 -0400 Received: from mx2.suse.de ([195.135.220.15]:49578 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731680AbgDAG2p (ORCPT ); Wed, 1 Apr 2020 02:28:45 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id F0C39AB3D; Wed, 1 Apr 2020 06:28:41 +0000 (UTC) Subject: Re: [PATCH v7 1/2] rpmsg: core: add API to get MTU To: Arnaud Pouliquen , Ohad Ben-Cohen , Bjorn Andersson , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linux-remoteproc@vger.kernel.org, Mathieu Poirier Cc: Suman Anna , Fabien DESSENNE , linux-stm32@st-md-mailman.stormreply.com, Alan Cox , xiang xiao References: <20200324170407.16470-1-arnaud.pouliquen@st.com> <20200324170407.16470-2-arnaud.pouliquen@st.com> From: Jiri Slaby Autocrypt: addr=jslaby@suse.com; prefer-encrypt=mutual; keydata= mQINBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABtBxKaXJpIFNsYWJ5 IDxqc2xhYnlAc3VzZS5jb20+iQI4BBMBAgAiBQJOkujrAhsDBgsJCAcDAgYVCAIJCgsEFgID AQIeAQIXgAAKCRC9JbEEBrRwSc1VD/9CxnyCYkBrzTfbi/F3/tTstr3cYOuQlpmufoEjCIXx PNnBVzP7XWPaHIUpp5tcweG6HNmHgnaJScMHHyG83nNAoCEPihyZC2ANQjgyOcnzDOnW2Gzf 8v34FDQqj8CgHulD5noYBrzYRAss6K42yUxUGHOFI1Ky1602OCBRtyJrMihio0gNuC1lE4YZ juGZEU6MYO1jKn8QwGNpNKz/oBs7YboU7bxNTgKrxX61cSJuknhB+7rHOQJSXdY02Tt31R8G diot+1lO/SoB47Y0Bex7WGTXe13gZvSyJkhZa5llWI/2d/s1aq5pgrpMDpTisIpmxFx2OEkb jM95kLOs/J8bzostEoEJGDL4u8XxoLnOEjWyT82eKkAe4j7IGQlA9QQR2hCMsBdvZ/EoqTcd SqZSOto9eLQkjZLz0BmeYIL8SPkgnVAJ/FEK44NrHUGzjzdkE7a0jNvHt8ztw6S+gACVpysi QYo2OH8hZGaajtJ8mrgN2Lxg7CpQ0F6t/N1aa/+A2FwdRw5sHBqA4PH8s0Apqu66Q94YFzzu 8OWkSPLgTjtyZcez79EQt02u8xH8dikk7API/PYOY+462qqbahpRGaYdvloaw7tOQJ224pWJ 4xePwtGyj4raAeczOcBQbKKW6hSH9iz7E5XUdpJqO3iZ9psILk5XoyO53wwhsLgGcrkCDQRO kueGARAAz5wNYsv5a9z1wuEDY5dn+Aya7s1tgqN+2HVTI64F3l6Yg753hF8UzTZcVMi3gzHC ECvKGwpBBwDiJA2V2RvJ6+Jis8paMtONFdPlwPaWlbOv4nHuZfsidXkk7PVCr4/6clZggGNQ qEjTe7Hz2nnwJiKXbhmnKfYXlxftT6KdjyUkgHAs8Gdz1nQCf8NWdQ4P7TAhxhWdkAoOIhc4 OQapODd+FnBtuL4oCG0c8UzZ8bDZVNR/rYgfNX54FKdqbM84FzVewlgpGjcUc14u5Lx/jBR7 ttZv07ro88Ur9GR6o1fpqSQUF/1V+tnWtMQoDIna6p/UQjWiVicQ2Tj7TQgFr4Fq8ZDxRb10 Zbeds+t+45XlRS9uexJDCPrulJ2sFCqKWvk3/kf3PtUINDR2G4k228NKVN/aJQUGqCTeyaWf fU9RiJU+sw/RXiNrSL2q079MHTWtN9PJdNG2rPneo7l0axiKWIk7lpSaHyzBWmi2Arj/nuHf Maxpc708aCecB2p4pUhNoVMtjUhKD4+1vgqiWKI6OsEyZBRIlW2RRcysIwJ648MYejvf1dzv mVweUa4zfIQH/+G0qPKmtst4t/XLjE/JN54XnOD/TO1Fk0pmJyASbHJQ0EcecEodDHPWP6bM fQeNlm1eMa7YosnXwbTurR+nPZk+TYPndbDf1U0j8n0AEQEAAYkCHwQYAQIACQUCTpLnhgIb DAAKCRC9JbEEBrRwSTe1EACA74MWlvIhrhGWd+lxbXsB+elmL1VHn7Ovj3qfaMf/WV3BE79L 5A1IDyp0AGoxv1YjgE1qgA2ByDQBLjb0yrS1ppYqQCOSQYBPuYPVDk+IuvTpj/4rN2v3R5RW d6ozZNRBBsr4qHsnCYZWtEY2pCsOT6BE28qcbAU15ORMq0nQ/yNh3s/WBlv0XCP1gvGOGf+x UiE2YQEsGgjs8v719sguok8eADBbfmumerh/8RhPKRuTWxrXdNq/pu0n7hA6Btx7NYjBnnD8 lV8Qlb0lencEUBXNFDmdWussMAlnxjmKhZyb30m1IgjFfG30UloZzUGCyLkr/53JMovAswmC IHNtXHwb58Ikn1i2U049aFso+WtDz4BjnYBqCL1Y2F7pd8l2HmDqm2I4gubffSaRHiBbqcSB lXIjJOrd6Q66u5+1Yv32qk/nOL542syYtFDH2J5wM2AWvfjZH1tMOVvVMu5Fv7+0n3x/9shY ivRypCapDfcWBGGsbX5eaXpRfInaMTGaU7wmWO44Z5diHpmQgTLOrN9/MEtdkK6OVhAMVenI w1UnZnA+ZfaZYShi5oFTQk3vAz7/NaA5/bNHCES4PcDZw7Y/GiIh/JQR8H1JKZ99or9LjFeg HrC8YQ1nzkeDfsLtYM11oC3peHa5AiXLmCuSC9ammQ3LhkfET6N42xTu2A== Message-ID: <356fe539-6ec4-6000-1f68-23404fc5d373@suse.com> Date: Wed, 1 Apr 2020 08:28:39 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200324170407.16470-2-arnaud.pouliquen@st.com> Content-Type: text/plain; charset=iso-8859-2 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24. 03. 20, 18:04, Arnaud Pouliquen wrote: > Return the rpmsg buffer MTU for sending message, so rpmsg users > can split a long message in several sub rpmsg buffers. > > Signed-off-by: Arnaud Pouliquen > Acked-by: Suman Anna > --- > drivers/rpmsg/rpmsg_core.c | 21 +++++++++++++++++++++ > drivers/rpmsg/rpmsg_internal.h | 2 ++ > drivers/rpmsg/virtio_rpmsg_bus.c | 10 ++++++++++ > include/linux/rpmsg.h | 10 ++++++++++ > 4 files changed, 43 insertions(+) > > diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c > index e330ec4dfc33..a6ef54c4779a 100644 > --- a/drivers/rpmsg/rpmsg_core.c > +++ b/drivers/rpmsg/rpmsg_core.c > @@ -283,6 +283,27 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, > } > EXPORT_SYMBOL(rpmsg_trysend_offchannel); > > +/** > + * rpmsg_get_mtu() - get maximum transmission buffer size for sending message. > + * @ept: the rpmsg endpoint > + * > + * This function returns maximum buffer size available for a single message. > + * > + * Return: the maximum transmission size on success and an appropriate error > + * value on failure. > + */ > + > +ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept) > +{ > + if (WARN_ON(!ept)) > + return -EINVAL; > + if (!ept->ops->get_mtu) > + return -ENOTSUPP; Hmm, I don't think all callers of tty_write_room() handle negative values... But some drivers also return negative values. There is some work to be done, adding to TODO. For the time being, I suggest returning 0 instead. thanks, -- js suse labs