From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from down.free-electrons.com ([37.187.137.238]:46562 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752087AbbDSPaO convert rfc822-to-8bit (ORCPT ); Sun, 19 Apr 2015 11:30:14 -0400 Date: Sun, 19 Apr 2015 17:30:06 +0200 From: Boris Brezillon To: Heiko =?UTF-8?B?U3TDvGJuZXI=?= Cc: Mike Turquette , Mikko Perttunen , Jonathan Corbet , Shawn Guo , ascha Hauer , David Brown , Daniel Walker , Bryan Huntsman , Tony Lindgren , Paul Walmsley , Liviu Dudau , Sudeep Holla , Lorenzo Pieralisi , Ralf Baechle , Max Filippov , Sylwester Nawrocki , Tomasz Figa , Barry Song , Viresh Kumar , Emilio =?UTF-8?B?TMOzcGV6?= , Maxime Ripard , Peter De Schrijver , Prashant Gaikwad , Stephen Warren , Thierry Reding , Alexandre Courbot , Tero Kristo , Ulf Hansson , Michal Simek , Philipp Zabel , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, linux-omap@vger.kernel.org, linux-mips@linux-mips.org, patches@opensource.wolfsonmicro.com, linux-rockchip@lists.infradead.org, linux-samsung-soc@vger.kernel.org, spear-devel@list.st.com, linux-tegra@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-media@vger.kernel.org, rtc-linux@googlegroups.com Subject: Re: [PATCH 1/2] clk: change clk_ops' ->round_rate() prototype Message-ID: <20150419173006.0ce6cfe0@bbrezillon> In-Reply-To: <7408975.lBcgZIN9hf@diego> References: <1429255769-13639-1-git-send-email-boris.brezillon@free-electrons.com> <1429255769-13639-2-git-send-email-boris.brezillon@free-electrons.com> <7408975.lBcgZIN9hf@diego> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-media-owner@vger.kernel.org List-ID: Hi Heiko, On Sun, 19 Apr 2015 14:13:04 +0200 Heiko Stübner wrote: > Hi Boris, > > Am Freitag, 17. April 2015, 09:29:28 schrieb Boris Brezillon: > > Clock rates are stored in an unsigned long field, but ->round_rate() > > (which returns a rounded rate from a requested one) returns a long > > value (errors are reported using negative error codes), which can lead > > to long overflow if the clock rate exceed 2Ghz. > > > > Change ->round_rate() prototype to return 0 or an error code, and pass the > > requested rate as a pointer so that it can be adjusted depending on > > hardware capabilities. > > > > Signed-off-by: Boris Brezillon > > --- > > On a rk3288-veyron-pinky with the fix described below: > Tested-by: Heiko Stuebner > > > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > > index fa5a00e..1462ddc 100644 > > --- a/drivers/clk/clk.c > > +++ b/drivers/clk/clk.c > > @@ -1640,8 +1643,10 @@ static struct clk_core *clk_calc_new_rates(struct > > clk_core *clk, &parent_hw); > > parent = parent_hw ? parent_hw->core : NULL; > > } else if (clk->ops->round_rate) { > > - new_rate = clk->ops->round_rate(clk->hw, rate, > > - &best_parent_rate); > > + if (clk->ops->round_rate(clk->hw, &new_rate, > > + &best_parent_rate)) > > + return NULL; > > + > > if (new_rate < min_rate || new_rate > max_rate) > > return NULL; > > } else if (!parent || !(clk->flags & CLK_SET_RATE_PARENT)) { > > This is using new_rate uninitialized when calling into the round_rate > callback. Which in turn pushed my PLLs up to 2.2GHz :-) Indeed, thanks for the fix. [...] > > > And as I've stumbled onto this recently too, the clock-maintainership has > expanded to Stephen Boyd and linux-clk@vger.kernel.org . Noted. I'll add Stephen and the new linux-clk ML in the recipient list next time. Best Regards, Boris -- Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com