From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Ripard Subject: Re: [PATCH 01/15] clk: sunxi-ng: Add check for minimal rate to NM PLLs Date: Mon, 26 Feb 2018 11:25:57 +0100 Message-ID: <20180226102557.7bgjs3txp7cbridn@flea.lan> References: <20180224214545.3740-1-jernej.skrabec@siol.net> <20180224214545.3740-2-jernej.skrabec@siol.net> <20180226093800.uwbo54wrdcwmsyzh@flea.lan> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1137822968==" Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Chen-Yu Tsai Cc: Mark Rutland , devicetree , Jernej Skrabec , David Airlie , Mike Turquette , linux-kernel , dri-devel , Stephen Boyd , linux-sunxi , Rob Herring , linux-clk , linux-arm-kernel List-Id: devicetree@vger.kernel.org --===============1137822968== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dxrtdxft72nv6clt" Content-Disposition: inline --dxrtdxft72nv6clt Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Feb 26, 2018 at 05:43:01PM +0800, Chen-Yu Tsai wrote: > On Mon, Feb 26, 2018 at 5:38 PM, Maxime Ripard > wrote: > > Hi, > > > > On Sat, Feb 24, 2018 at 10:45:31PM +0100, Jernej Skrabec wrote: > >> Some NM PLLs doesn't work well when their output clock rate is set bel= ow > >> certain rate. > >> > >> Add support for that constrain. > > > > In such a case, you should round the rate to the minimum the clock can > > operate at, and not return an error. >=20 > That's true for round_rate. But what's the expected behavior of set_rate? > AFAIK we presume all users call round_rate before set_rate, but that does= n't > seem to be true all the time. One of the first things that happens during a set_rate is a round_rate: https://elixir.bootlin.com/linux/v4.16-rc3/source/drivers/clk/clk.c#L1873 Maxime --=20 Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com --dxrtdxft72nv6clt Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEE0VqZU19dR2zEVaqr0rTAlCFNr3QFAlqT4LQACgkQ0rTAlCFN r3T82Q//XfVSf/LYhtSjfNluMQUsBGgfDZcrFQEQfFSe5p1v72zjU292NQonhjQa EPas8HKpm1lpKz8b1cEzT8VSdi4/JgkES4FXDfdGfzkZFKgU/EQUljAgMyrVmgpJ 2kKgKtOVg3PO0VlzFXcTBcqPn/5TVDnPNG7w6BjmLMhpkhSKiZ9XqxGdZNMBEfcW ck+Nhg6wd/vTbBxRyWmuZIh+Dp2Wk2upzejNG/vm7OS7z0AMW85FoA6LrtbEnkD9 v9lcEdJhDmAEy9lhl8vZ2qdjNbbqtIN4UXd4p3nUVyyOiEULFdN7OBRNSZYnOFrI 9Ac1X8LSfK1/1N6kHdoinIgEv/ZMT7vHXk6WG8x80YS8mAv/nh4HRfTdTNnWP9mg JeUYl9KNQ0cUJsTxPGTOfyduv6mAgQRgwYrHJgVF5WI7ovrU+MX7hJAKp/YlXbhn mHugHcCTJh4OO/sLhq/f8zH+ZX+HxuEOreReRl0scWbnFLV1Okck7DU1aNT77LK1 B5Qj0mnerD1bqBZtxxAuj+v/wA1CE+W+iMwi7O+YBawuyDu4naO9WTlpZsfkNS9H 8ZAFzYZbcebdO3JO6+To9tq2KdGYijYz5OpCnhMJsvZb/z9AgeBaOHNuJnWgIkBt r9m734o5BlBk172h2J44SxN6HoZ3Q540EuS2T6xJJV2Hr9cyySE= =7CGv -----END PGP SIGNATURE----- --dxrtdxft72nv6clt-- --===============1137822968== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============1137822968==--