From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B009A19F11F for ; Fri, 28 Mar 2025 07:23:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743146601; cv=none; b=MLaZjUgie3FW+feHSpOMe7yif34qwtFjmODkO+pX778sVj7cfs3S+k65HNJfEGtGqgUIegeANBReNdJQkDIh3Ry/uEO2mVuPcS1j8D6trOmhgKaWD4Rn4dIqJqbEQYQp5TvxfMEbO+QituAZ7u6B0emya2PAveWy4z6FjuPWl0E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1743146601; c=relaxed/simple; bh=JREqmQ3F44uxPOvDqNR52TR0Yop4pEtWE1iR0/YLCZ8=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jfPdsthbRlVeX14A0BLj+KKFeygYfhAPscS1L968/2xGEITPwsv3Jo/q6WXXtHunjhw1WxNpmwVbboVqu0cTcFqRipuo5yQuEx5245qS9SEYW2A4wSGKg8I/JAtayo9DjHJdhrgF++mODjvII8hx5tua73rmnAY2dWtHceMDvE8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ty43D-0000Nn-Lv; Fri, 28 Mar 2025 08:22:47 +0100 Received: from moin.white.stw.pengutronix.de ([2a0a:edc0:0:b01:1d::7b] helo=bjornoya.blackshift.org) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1ty439-0023qP-1p; Fri, 28 Mar 2025 08:22:43 +0100 Received: from pengutronix.de (p5b1645f7.dip0.t-ipconnect.de [91.22.69.247]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange secp256r1 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 1DB853E85BD; Fri, 28 Mar 2025 07:22:43 +0000 (UTC) Date: Fri, 28 Mar 2025 08:22:42 +0100 From: Marc Kleine-Budde To: Ming Yu Cc: tmyu0@nuvoton.com, lee@kernel.org, linus.walleij@linaro.org, brgl@bgdev.pl, andi.shyti@kernel.org, mailhol.vincent@wanadoo.fr, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, wim@linux-watchdog.org, linux@roeck-us.net, jdelvare@suse.com, alexandre.belloni@bootlin.com, linux-kernel@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-rtc@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: [PATCH v8 4/7] can: Add Nuvoton NCT6694 CANFD support Message-ID: <20250328-smart-thundering-asp-2536b0-mkl@pengutronix.de> References: <20250225081644.3524915-1-a0282524688@gmail.com> <20250225081644.3524915-5-a0282524688@gmail.com> <20250227-spicy-grebe-of-dignity-68c847-mkl@pengutronix.de> <20250317-cuttlefish-of-simple-champagne-ee666c-mkl@pengutronix.de> <20250326-inventive-lavender-carp-1efca5-mkl@pengutronix.de> <20250327-awesome-mutant-cuscus-0f0314-mkl@pengutronix.de> Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="a4tssny7k3xmom4i" Content-Disposition: inline In-Reply-To: X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-gpio@vger.kernel.org --a4tssny7k3xmom4i Content-Type: text/plain; protected-headers=v1; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH v8 4/7] can: Add Nuvoton NCT6694 CANFD support MIME-Version: 1.0 On 28.03.2025 10:37:33, Ming Yu wrote: > Marc Kleine-Budde =E6=96=BC 2025=E5=B9=B43=E6=9C=882= 7=E6=97=A5 =E9=80=B1=E5=9B=9B =E4=B8=8B=E5=8D=883:25=E5=AF=AB=E9=81=93=EF= =BC=9A > > > > On 27.03.2025 13:38:22, Ming Yu wrote: > > > Marc Kleine-Budde =E6=96=BC 2025=E5=B9=B43=E6=9C= =8827=E6=97=A5 =E9=80=B1=E5=9B=9B =E4=B8=8A=E5=8D=881:41=E5=AF=AB=E9=81=93= =EF=BC=9A > > > > > > > > > > > > > + priv->can.clock.freq =3D can_clk; > > > > > > > > > + priv->can.bittiming_const =3D &nct6694_can_bittimin= g_nominal_const; > > > > > > > > > + priv->can.data_bittiming_const =3D &nct6694_can_bit= timing_data_const; > > > > > > > > > + priv->can.do_set_mode =3D nct6694_can_set_mode; > > > > > > > > > + priv->can.do_get_berr_counter =3D nct6694_can_get_b= err_counter; > > > > > > > > > + priv->can.ctrlmode_supported =3D CAN_CTRLMODE_LOOPB= ACK | > > > > > > > > > + CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_BERR= _REPORTING | > > > > > > > > > + CAN_CTRLMODE_FD | CAN_CTRLMODE_FD_NON_ISO; > > > > > > > > > > > > > > > > Does your device run in CAN-FD mode all the time? If so, pl= ease use > > > > > > > > can_set_static_ctrlmode() to set it after priv->can.ctrlmod= e_supported > > > > > > > > and remove CAN_CTRLMODE_FD from ctrlmode_supported. > > > > > > > > > > > > > > > > > > > > > > Our device is designed to allow users to dynamically switch b= etween > > > > > > > Classical CAN and CAN-FD mode via ip link set ... fd on/off. > > > > > > > Therefore, CAN_CTRLMODE_FD needs to remain in ctrlmode_suppor= ted, and > > > > > > > can_set_static_ctrlmode() is not suitable in this case. > > > > > > > Please let me know if you have any concerns about this approa= ch. > > > > > > > > > > > > Where do you evaluate if the user has configured CAN_CTRLMODE_F= D or not? > > > > > > > > > > > > > > > > Sorry, I was previously confused about our device's control mode.= I > > > > > will use can_set_static_ctrlmode() to set CAN_FD mode in the next > > > > > patch. > > > > > > > > Does your device support CAN-CC only mode? Does your device support= to > > > > switch between CAN-CC only and CAN-FD mode? > > > > > > > > > > Our device supports both CAN-CC and CAN-FD mode. > > > > This doesn't answer my question: > > > > Does your device support CAN-CC only mode? >=20 > It can dynamically switch between CAN-CC and CAN-FD mode when > trasmitting or receiving, depending on whether the nct6694_can_frame > passs the flag with NCT6694_CAN_FRAME_FLAG_FD. Ok, but what about the receive path? Does the device support CAN-CC only mode? Will it throw an error, if it receives a CAN-FD frame? regards, Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Embedded Linux | https://www.pengutronix.de | Vertretung N=C3=BCrnberg | Phone: +49-5121-206917-129 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 | --a4tssny7k3xmom4i Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEn/sM2K9nqF/8FWzzDHRl3/mQkZwFAmfmTj8ACgkQDHRl3/mQ kZxbBggAnvTDCDToJYkOojptUT65lDvDa1RdwRbTO+7MEEyuklVxALUQJmpsq1Yw Aw4gKcwEZE1Q3vdlXR9kF4hUCKczWT5QxeqCW9M/qEfSXgNXhX8CCHVDzl5b7Om+ kB+tiH7jitYhp2s9dK0Muj/hl4QuOL35OW0Ayn6G/Pd/fKjNJlf4to2ziatUFtk6 nWNfPrk9LhQq9B/Fy5yGxDpt7WwPU3MUMaYWHZSvSMyPawBPpj6nYtlXRn9FeVUK EEZIiOVW/orW9H5nu5XeGXbYM5OdwNqh83rqW94yYoeyE4A+2CX9UZ+kkLpabh7v Xz6Zr0RWQWzVT0cOQWKPGt0vY3Iw0Q== =Op9R -----END PGP SIGNATURE----- --a4tssny7k3xmom4i--