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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 8F9A2C433ED for ; Wed, 28 Apr 2021 10:47:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5EDE1613F7 for ; Wed, 28 Apr 2021 10:47:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239536AbhD1KsX (ORCPT ); Wed, 28 Apr 2021 06:48:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40836 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239552AbhD1KsV (ORCPT ); Wed, 28 Apr 2021 06:48:21 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7EA7CC06138A for ; Wed, 28 Apr 2021 03:47:36 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lbhjC-0007uO-CH; Wed, 28 Apr 2021 12:47:34 +0200 Received: from pengutronix.de (unknown [IPv6:2a03:f580:87bc:d400:4048:54d7:3c62:4ce5]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-384) server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) (Authenticated sender: mkl-all@blackshift.org) by smtp.blackshift.org (Postfix) with ESMTPSA id 5CD7B618789; Wed, 28 Apr 2021 10:47:33 +0000 (UTC) Date: Wed, 28 Apr 2021 12:47:32 +0200 From: Marc Kleine-Budde To: Oliver Hartkopp Cc: linux-can@vger.kernel.org, "Sottas Guillaume (LMB)" Subject: Re: [PATCH] can: isotp: return -ECOMM on FC timeout on TX path Message-ID: <20210428104732.bbmklgyuto5oi3kd@pengutronix.de> References: <20210428090914.252967-1-mkl@pengutronix.de> <20210428091224.lsqf4tttd7uijdms@pengutronix.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="rife7ladlqdowiw3" Content-Disposition: inline In-Reply-To: X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org --rife7ladlqdowiw3 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 28.04.2021 12:24:32, Oliver Hartkopp wrote: > > Maybe the way to trigger the sk_error_report(sk) we might return '-1' > > while the error is then propagated inside errno. >=20 > I added some debug print in isotpsend: >=20 > diff --git a/isotpsend.c b/isotpsend.c > index 3ea574c..c2937fa 100644 > --- a/isotpsend.c > +++ b/isotpsend.c > @@ -45,10 +45,11 @@ > #include > #include > #include > #include > #include > +#include >=20 > #include > #include > #include > #include > @@ -252,10 +253,11 @@ int main(int argc, char **argv) > buf[buflen] =3D ((buflen % 0xFF) + 1) & 0xFF; > } >=20 >=20 > retval =3D write(s, buf, buflen); > + printf("retval %d errno %d\n", retval, errno); Note: in user space errno is only valid if retval is "-1"... > if (retval < 0) { > perror("write"); > return retval; > } >=20 >=20 > $ date +%S.%N && ./isotpsend vcan0 -s 123 -d 321 -D 44 -b && date +%S.%N > 43.269173590 > retval 44 errno 0 > 44.271162277 >=20 > So it waits for the timeout as required by the '-b' option - but the errno > is not set :-/ I'm not sure what we have to return in the kernel... Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung West/Dortmund | Phone: +49-231-2826-924 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | --rife7ladlqdowiw3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEK3kIWJt9yTYMP3ehqclaivrt76kFAmCJPUEACgkQqclaivrt 76mRGgf/TDKXSgvwLMgzM6JV+gcc/XujR+2ofvJX6Po46aqdKgUB0nkI1r299h4r g4bICW7DDoa4EyKeCAb8wYA0TuDbGs5ehJ5cDoGwAIDFXjPs+5WwlGHDxxZGrX7m 80yfnrGqKhdSawDM4qcXwmp1GHxli7mXCg9BePoymd/V60N7VmJ6QR+TiTObDIVs lO82UsGRZa3oCpkeMSuASs4WqcMfij1cRCqp2mnjVmADuRwzcU1kfxsN8o8JhT37 sG7WrIWeP/0zaFXGjT9pFPD7ejdPZjeWYHTWWgopZI00nmQDuhvwTtVRmfutiW7s 0cXpdkLCumnMwkDnG3LwvBMk6IuORg== =fznx -----END PGP SIGNATURE----- --rife7ladlqdowiw3--