From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D2AC4376BCC for ; Tue, 9 Jun 2026 16:11:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781021509; cv=none; b=J9PMZ6ELQaSale7eAGIcp7puU5tDOjrC39HFq5XMnvNB2JFK+2moKuc4IK9Ykt7uHAHXaSUaHfioUa3sHoF4r03d0Hjn8ZkdMniezlaQSrHydBRoLdcJxFVidcmPa93wxEakumczGryIUnWO35rN85GWqEJqpNljKbQtNhPoACw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781021509; c=relaxed/simple; bh=00SS/Xzmmz5cOQhOWuM8lMZBCvPmsMinB6INBMN9QdA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=s30KLmiFQFWufBDc2jHKZJyKKaOxtzrUB6FmS5OCiXt1Pr3FEAIYBByKHGdPW+QEa3jUnhricHlGGghRznZMrbh8Z5OlKeb1bWhE6DsUvhpqmopCrSEtYm0WIJ5iHMRSSbiTmEj7pf0t1Zux/RPbdbEWMUVLC8BMJCiunEyCUSQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=CraomqsS; arc=none smtp.client-ip=209.85.214.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="CraomqsS" Received: by mail-pl1-f180.google.com with SMTP id d9443c01a7336-2bf114b0cf9so51741405ad.2 for ; Tue, 09 Jun 2026 09:11:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1781021507; x=1781626307; darn=vger.kernel.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=OtS0v5RJiVwlhfJHAeudQgGTHcf4Qlic2DpfgDHvJeg=; b=CraomqsSRvatQC+q3r5mncybj8+G7RtFk53Qg11tPeG+HtN9uNmVRCuzxlnbr32mXi TwnJvvIkqQyfTG8COX8G1GxRtsHiOHdX9FAdOd/q2k1E2y3+Un2rVNOJxIFNdRZ1qZsA VmQjhvFIwdVDie8jphIXpJsKbuWwpga9ZeoIv/KkWDMemiX8MEK9vh/cYcqCWszedIDs wENS2le7O8NpZRUZ/MbidV1/jZIXddIAnd9hWYSXEBPNamYNoc9piaPE2q4VMMB8vPh2 PC+mdvXmulC4+lye+wp/S2bEw4eOLJ3Wak6ru3ibMnHRhteyUhVZa/akLoI85Dc/j9UU RNGQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781021507; x=1781626307; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=OtS0v5RJiVwlhfJHAeudQgGTHcf4Qlic2DpfgDHvJeg=; b=nlbQMkwoXuOAGxluHBWElsegHHPqbhGZKuchRlk7b96z4UkdD+kcdidqCtMyBElge0 1llkTEso5q6u7VfuWIoU1+AIJsYSy/87V9r6k/sxdjJ7vwZGkaZnvTlQH5EgF7gsCUUZ bUMyXJnjvOEjwh4nsnOz1cR+jAbDuggRrbiJMf13y7GlsoyI4zEqSH9igxKbtw8s8wyB Phwp18B5dHX5xD2weA/YTcip/G0w3IVCAMEDugG3v+4uzCaeB9OF1f1Pwm362N3jaQmw Mfqiz5D/J3EZQ+IBYaP+YSiQ7XGZZVZR3Wkzna39bxWtT5M1cuF0l29ean++QN3Tg8wq m2FQ== X-Forwarded-Encrypted: i=1; AFNElJ+rVbmMzRSkJpxZMqjlBrZKBL762qolT1ixLSDO+A/X8rI5n2IbFnO3FAHJe8DNfDXjModfyQn8hFByeSY=@vger.kernel.org X-Gm-Message-State: AOJu0Yyi+p0xJnu6bXaDMrvAm52QEBIpcmtYjXApCO1/2mriTjjNPwd+ XMtO/6UDlDD19xKWGyiUhmKQ7JhHX9m48LIx04OMoU3O+k11OTqmBo862ofifVBeOr4= X-Gm-Gg: Acq92OH7HeDlEQS7hzIyUY4PuWOuSBtOykOCpD861NQefbTtRUK9b1rGkP8Jaed1ycy pH2NBqn5wb6mtO/BKcUpScmRSChOZHbKagYIh7U92kX3breDOMLvAC4c26sjeQb2LSmJFE6nJh7 rtcCrxpyK54IVIuLO0dfIR+6+DzmB31buOqbkE8JiAh6qmKsBb/8VVFaNhYc/td5oajZkfqHep8 BTTQeP8xzV0lrj85SvStyJskf5prHRgftu9D992VC8dPfbIV2bnZINtRElWLocgOWvSjn0uKClD f5a3hFnRkjVoKjmtBTdEmeXGboD2IVuMjgGR3lGusUPmdQhmoWMS/MxkPSkV/2pznVkWZ5HOimo HBs3IxUjiYKgOsiu/Xnrkx4g7rdP4YpN6niX5KeAhYD428zxuVUtfoJA92dt6UIWpRDpFBc/eeI wB4eDlm4nh5wjxhXhsm6UQgoLbC1LEULo3P1ML X-Received: by 2002:a17:903:1aef:b0:2c2:7e17:39f6 with SMTP id d9443c01a7336-2c27e173ecfmr105901915ad.36.1781021507165; Tue, 09 Jun 2026 09:11:47 -0700 (PDT) Received: from p14s ([2604:3d09:148c:c800:7f00:843c:9d87:e9dc]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2c164f6d395sm294099785ad.17.2026.06.09.09.11.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Jun 2026 09:11:46 -0700 (PDT) Date: Tue, 9 Jun 2026 10:11:44 -0600 From: Mathieu Poirier To: tanmay.shah@amd.com Cc: Arnaud POULIQUEN , andersson@kernel.org, linux-kernel@vger.kernel.org, linux-remoteproc@vger.kernel.org, divin.raj@arm.com Subject: Re: [PATCH v3 4/4] samples: rpmsg: add MTU size info Message-ID: References: <20260529164327.1827121-1-tanmay.shah@amd.com> <20260529164327.1827121-5-tanmay.shah@amd.com> <44c03148-9ff2-4fad-846d-ffe3d71adac1@foss.st.com> 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=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Jun 04, 2026 at 05:28:13PM -0500, Shah, Tanmay wrote: > > > On 6/2/2026 3:34 AM, Arnaud POULIQUEN wrote: > > > > > > On 5/29/26 18:43, Tanmay Shah wrote: > >> RPMsg MTU size can be variable now and no longer hardcoded to 512 bytes. > >> Add log to the sample driver that prints current MTU size of the rpmsg > >> buffer. > >> > >> Signed-off-by: Tanmay Shah > >> --- > >> > >> Changes in v3: > >>    - Check for error when retrieving MTU size > >>    - %s/mtu/MTU/ > >> > >>   samples/rpmsg/rpmsg_client_sample.c | 9 +++++++++ > >>   1 file changed, 9 insertions(+) > >> > >> diff --git a/samples/rpmsg/rpmsg_client_sample.c b/samples/rpmsg/ > >> rpmsg_client_sample.c > >> index ae5081662283..55afa53189af 100644 > >> --- a/samples/rpmsg/rpmsg_client_sample.c > >> +++ b/samples/rpmsg/rpmsg_client_sample.c > >> @@ -52,6 +52,7 @@ static int rpmsg_sample_probe(struct rpmsg_device > >> *rpdev) > >>   { > >>       int ret; > >>       struct instance_data *idata; > >> +    ssize_t mtu; > >>         dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n", > >>                       rpdev->src, rpdev->dst); > >> @@ -62,6 +63,14 @@ static int rpmsg_sample_probe(struct rpmsg_device > >> *rpdev) > >>         dev_set_drvdata(&rpdev->dev, idata); > >>   +    mtu = rpmsg_get_mtu(rpdev->ept); > >> +    if (mtu < 0) { > >> +        dev_warn(&rpdev->dev, "invalid rpmsg MTU size = %ld\n", mtu); > >> +        return mtu; > >> +    } > >> + > >> +    dev_info(&rpdev->dev, "rpmsg MTU size = %ld\n", mtu); > >> + > > > > Do you really need this commit? rpmsg_send should return an error if the > > buffer size is insufficient [1]. > > > > [1] https://elixir.bootlin.com/linux/v7.0.10/source/drivers/rpmsg/ > > virtio_rpmsg_bus.c#L517 > > > > Here, I just want to demonstrate rpmsg_get_mtu() API. Now we can have a > configurable size of the RPMsg buffer. So rpmsg_get_mtu() API can be > used to check correct buffer length before even using rpmsg_send() API. > > I think I should check msg length against mtu size as well. Do you plan on sending a new revision of this set or should I move forward with this one? > > > > Regards, > > Arnaud > > > >>       /* send a message to our remote processor */ > >>       ret = rpmsg_send(rpdev->ept, MSG, strlen(MSG)); > >>       if (ret) { > > >