From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH v3 4/4] can: kvaser_usb: Add support for the Usbcan-II family Date: Fri, 09 Jan 2015 15:05:49 +0100 Message-ID: <54AFE03D.5040509@pengutronix.de> References: <20141223154654.GB6460@vivalin-002> <20150105174910.GA6304@linux> <20150105175206.GB6304@linux> <20150105175713.GC6304@linux> <20150105183131.GD6304@linux> <54AE6FC1.6050007@pengutronix.de> <20150109030657.GA1791@vivalin-002> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="KF4kD39KBoUua5OAQf1OMwpNjnjsVE3c2" Cc: Olivier Sobrie , Oliver Hartkopp , Wolfgang Grandegger , "David S. Miller" , Paul Gortmaker , Linux-CAN , netdev , LKML To: "Ahmed S. Darwish" Return-path: In-Reply-To: <20150109030657.GA1791@vivalin-002> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --KF4kD39KBoUua5OAQf1OMwpNjnjsVE3c2 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 01/09/2015 04:06 AM, Ahmed S. Darwish wrote: >>> >>> cf->can_id |=3D CAN_ERR_CRTL; >>> cf->data[1] =3D CAN_ERR_CRTL_RX_OVERFLOW; >>> >>> stats->rx_over_errors++; >>> stats->rx_errors++; >>> >>> netif_rx(skb); >>> >>> stats->rx_packets++; >>> stats->rx_bytes +=3D cf->can_dlc; >> >> Another patch would be not to touch cf after netif_rx(), please >> move the stats handling before calling netif_rx(). Same applies to >> the kvaser_usb_rx_can_msg() function. > BTW, is it guaranteed from the SocketCAN stack that netif_rx() netif_rx() is the generic networking stack already. > will never return NET_RX_DROPPED? Because if no guarantee > exists, I guess below fragment cannot be completely correct? No, it's not guaranteed... >=20 > stats->rx_packets++; > stats->rx_bytes +=3D cf->can_dlc; > netif_rx(skb); >=20 > On the other hand, I don't see evan a single CAN driver checking > netif_rx() return value, so maybe such a check is an overkill... A quick look shows that almost no ethernet or wireless drivers take care about the return value. In case of a RX_DROPPED some increase a drop counter, though. Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --KF4kD39KBoUua5OAQf1OMwpNjnjsVE3c2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJUr+A9AAoJECte4hHFiupUUvIP/RPFuWMts6qYX7knfvztzjjd Ogow3/KZF5H9lLWgxQh3sYZ+S6p/BMaSkVLACrPCR8VXyI/uDiSrtsrBkh6T2fk0 aHu7bxU6UAeBk1cgtMMu3EJZ8aFmLw1r0gi9WQ3TFE68JlFqUQQ63MRVvsEJfMgx bWHdIIv9maalC01eEmRtfYHonBJuUJw3zahfbJStHxlgTBjdyG/48tDk4y9jPbCh b4Hv+VekDE+tQ58BB7+oTeCoYWfogpTMtu/N+43o2LGwGleW2UQPt8rCC7/wovJW Pm4uqpL0kO4B9lpoeLirXxEGhq5m536uqEgWn04obhoTpahRVOWxNUYn2d3wu67L P2M6PfJc65WNwbdbh+P36rcmuoMSPabVi5gU/a1HZzoy+S00rF9DYmbedDtTdmkL 7vynsNWulwgm9HaAU6Y7w2n7qSpzzV+a7L3TpyCbFHb95LxCtD1a+nAwShPC2+ik wpHJpxvsS1Ym7hvIRyzpVdVL0P9HO4tEraV1nI1Z5eXUz2czjWJ1c2BmwNirK9Tu Pj0HAleSUrXAvdSgK3sgtgg01bH6RF1rQPRq0dAPwDdLKBhDm0+UczWeBGvQR9Vt gEWtsghkXEouFlSudqGUNkRRDMH30n/hyL96pQ1iFh8+KGGI6JnO7tw+mwD8nUL9 wQKIu3jo+dddyBO5RL73 =7GlW -----END PGP SIGNATURE----- --KF4kD39KBoUua5OAQf1OMwpNjnjsVE3c2--