From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH 1/2] can: rcar_can: Add r8a7795 support Date: Mon, 29 Feb 2016 11:00:09 +0100 Message-ID: <56D416A9.6080608@pengutronix.de> References: <1456737661-20538-1-git-send-email-ramesh.shanmugasundaram@bp.renesas.com> <1456737661-20538-2-git-send-email-ramesh.shanmugasundaram@bp.renesas.com> <56D411A5.9070706@pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="2XsOGtBhgUTBHMXDGWjOlmjSLgMgT41d6" Cc: "linux-renesas-soc@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-can@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "netdev@vger.kernel.org" , Chris Paterson To: Ramesh Shanmugasundaram , "wg@grandegger.com" , "horms@verge.net.au" , "magnus.damm@gmail.com" , "robh+dt@kernel.org" , "pawel.moll@arm.com" , "mark.rutland@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" Return-path: In-Reply-To: Sender: linux-renesas-soc-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --2XsOGtBhgUTBHMXDGWjOlmjSLgMgT41d6 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 02/29/2016 10:56 AM, Ramesh Shanmugasundaram wrote: >> On 02/29/2016 10:21 AM, Ramesh Shanmugasundaram wrote: >>> Added r8a7795 SoC support. >>> >>> For smoother bit timing calculation, the rounded clock frequency is >> used. >> >> Why this? From my point of view this introduces a clock error. >=20 > Thanks for the comments.=20 >=20 > Without the rounded clock, can_calc_bittiming returns different BRP > values and reports high sampling error percentage. However, the > rounded clock shows no such issues and it works fine for all > bitrates. >=20 > Below is an e.g. from my board for an input clock differs by 2Hz. I think it's better to fix the algorithm. I'll look into it. 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 | --2XsOGtBhgUTBHMXDGWjOlmjSLgMgT41d6 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBCgAGBQJW1BapAAoJED07qiWsqSVqx0gH+wdaVApbZr7dQF0+4VnzwZMd +MLQ+n44pTm/XfDrhnPuMA3Y/oAZJ57620LPQIOfG9PZEtlSOu69q9p2udjbFfFz Oo8rrKthpfT4c9AhxBAXaGSIYoIPPSKooEuslk8lV6cttHxPX2aOkBoxOCZS0CVf GLREMcTjcQtT6rDmocV+djeAdRg4zMS/Nev73+Cu2GtlG72xgzQAxCbRCom5c3Ef lPMbm9qMR2pPIFtgYjUwUNnyiz/TctPW/nlw2ycQkU5aBaDD/ZqXVP9QkbIoN2CI DAcRrvRgMCSBDQxVwLcN7oRArKR1TLLAIWZB1AuALEovr0hD9JLhFvGzAzZeuiI= =Ue8T -----END PGP SIGNATURE----- --2XsOGtBhgUTBHMXDGWjOlmjSLgMgT41d6--