From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752021AbeB1Hg5 (ORCPT ); Wed, 28 Feb 2018 02:36:57 -0500 Received: from mail.bootlin.com ([62.4.15.54]:51937 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751907AbeB1Hez (ORCPT ); Wed, 28 Feb 2018 02:34:55 -0500 Date: Wed, 28 Feb 2018 08:34:40 +0100 From: Maxime Ripard To: Jernej Skrabec Cc: wens@csie.org, airlied@linux.ie, robh+dt@kernel.org, mark.rutland@arm.com, mturquette@baylibre.com, sboyd@kernel.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH v2 01/16] clk: sunxi-ng: Add check for minimal rate to NM PLLs Message-ID: <20180228073440.6ejo3wjdqag6h4nl@flea> References: <20180227222701.9716-1-jernej.skrabec@siol.net> <20180227222701.9716-2-jernej.skrabec@siol.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="jbftow7kteudva7c" Content-Disposition: inline In-Reply-To: <20180227222701.9716-2-jernej.skrabec@siol.net> User-Agent: NeoMutt/20180223 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --jbftow7kteudva7c Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi, On Tue, Feb 27, 2018 at 11:26:46PM +0100, Jernej Skrabec wrote: > Some NM PLLs doesn't work well when their output clock rate is set below > certain rate. >=20 > Add support for that constrain. >=20 > Signed-off-by: Jernej Skrabec > --- > drivers/clk/sunxi-ng/ccu_nm.c | 11 +++++++---- > drivers/clk/sunxi-ng/ccu_nm.h | 27 +++++++++++++++++++++++++++ > 2 files changed, 34 insertions(+), 4 deletions(-) >=20 > diff --git a/drivers/clk/sunxi-ng/ccu_nm.c b/drivers/clk/sunxi-ng/ccu_nm.c > index a16de092bf94..7fc743c78c1b 100644 > --- a/drivers/clk/sunxi-ng/ccu_nm.c > +++ b/drivers/clk/sunxi-ng/ccu_nm.c > @@ -20,7 +20,7 @@ struct _ccu_nm { > }; > =20 > static void ccu_nm_find_best(unsigned long parent, unsigned long rate, > - struct _ccu_nm *nm) > + unsigned long min_rate, struct _ccu_nm *nm) > { > unsigned long best_rate =3D 0; > unsigned long best_n =3D 0, best_m =3D 0; > @@ -30,7 +30,7 @@ static void ccu_nm_find_best(unsigned long parent, unsi= gned long rate, > for (_m =3D nm->min_m; _m <=3D nm->max_m; _m++) { > unsigned long tmp_rate =3D parent * _n / _m; > =20 > - if (tmp_rate > rate) > + if (tmp_rate > rate || tmp_rate < min_rate) > continue; > =20 > if ((rate - tmp_rate) < (rate - best_rate)) { > @@ -117,6 +117,9 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsi= gned long rate, > if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) > rate *=3D nm->fixed_post_div; > =20 > + if (rate < nm->min_rate) > + rate =3D nm->min_rate; > + I guess you can just return there. There's no point in trying to find the factors at this point, since the minimum should be a value that can be reached. > if (ccu_frac_helper_has_rate(&nm->common, &nm->frac, rate)) { > if (nm->common.features & CCU_FEATURE_FIXED_POSTDIV) > rate /=3D nm->fixed_post_div; > @@ -134,7 +137,7 @@ static long ccu_nm_round_rate(struct clk_hw *hw, unsi= gned long rate, > _nm.min_m =3D 1; > _nm.max_m =3D nm->m.max ?: 1 << nm->m.width; > =20 > - ccu_nm_find_best(*parent_rate, rate, &_nm); > + ccu_nm_find_best(*parent_rate, rate, nm->min_rate, &_nm); Therefore, you don't need to change the prototype there either. Maxime --=20 Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com --jbftow7kteudva7c Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE0VqZU19dR2zEVaqr0rTAlCFNr3QFAlqWW4wACgkQ0rTAlCFN r3TU/BAAmxBKw7Wvwd44uNICrnv1n/tKtG72EEdkJvG4B8OqXY69KckH7941DM9h YfujkHMsFqghmXCdMzxunXNHegSy6lM3aNMHQBXfOOj4drBW37WQMyZCc9jBUoAI DlmEraJZJDoA1sSSL/BIHSDxlM2EGzmhtB3RZrlcOdNGSPldAqgnEC28NwYbuZxP RMAsvwnyL39RVLZy3kSrJ6SNMdcFVvNNbueQhUrFrJAd/bpGbfBNJzj2uUPVODVV cwVGbqOe5z0Zno6O7Tp3Zd0+wKC1YwqQ6+K/MYzbXn5p5LIZLu+CcJvk9C2LEj3y /tY/XKU++1PSbHdbYIN7ZgNLVrTf9/3lyazgJcm/Wt9D5IplHKyDGZDwTFpW36fX R41WQS6YW1i3LJMd4qUBVlZuLtlVLceX6XDl9wxkQAwkSG3dyKPMBzEjVj2w+XUc OvNwIxwqmCdAcn12ZpRc3EAisKFzfcDJlMuXCIhKNwvddtGLsbLzXxvLTZUuJtmo nsBefriY+5d28sPucEVHtaYlz3276yF3dCi+j4JHrujdROhhuXud/WDPlBT2BecL btXOaCKZlbxrXAj2/ZXPz0iKTR2bx9CSGqfBIkkVZ+wfume+72fKpK3cXe3hekPM 2s8bQ75DlSaEbcTQXNhgzJ8at+fFm9LDQi6MsW57x6hQBnbbzoI= =WPSn -----END PGP SIGNATURE----- --jbftow7kteudva7c--