From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tero Kristo Subject: Re: [RFC PATCH] clk: ti: set CLK_SET_RATE_NO_REPARENT for ti,mux-clock Date: Thu, 19 Jun 2014 14:33:14 +0300 Message-ID: <53A2CA7A.60206@ti.com> References: <1402992272-21413-1-git-send-email-tomi.valkeinen@ti.com> <1402992272-21413-2-git-send-email-tomi.valkeinen@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:47175 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757273AbaFSLc6 (ORCPT ); Thu, 19 Jun 2014 07:32:58 -0400 In-Reply-To: <1402992272-21413-2-git-send-email-tomi.valkeinen@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Tomi Valkeinen , Paul Walmsley , Mike Turquette , linux-omap@vger.kernel.org Cc: Nishanth Menon , Felipe Balbi On 06/17/2014 11:04 AM, Tomi Valkeinen wrote: > When setting the rate of a clock, by default the clock framework will > change the parent of the clock to the most suitable one in > __clk_mux_determine_rate() (most suitable by looking at the clock rate). > > This is a rather dangerous default, and causes problems on AM43x when > using display and ethernet. There are multiple ways to select the clock > muxes on AM43x, and some of those clock paths have the same source > clocks for display and ethernet. When changing the clock rate for the > display subsystem, the clock framework decides to change the display mux > from the dedicated display PLL to a shared PLL which is used by the > ethernet, and then changes the rate of the shared PLL, breaking the > ethernet. > > As I don't think there ever is a case where we want the clock framework > to automatically change the parent clock of a clock mux, this patch sets > the CLK_SET_RATE_NO_REPARENT for all ti,mux-clocks. > > Signed-off-by: Tomi Valkeinen > --- > drivers/clk/ti/mux.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/clk/ti/mux.c b/drivers/clk/ti/mux.c > index 0197a478720c..e9d650e51287 100644 > --- a/drivers/clk/ti/mux.c > +++ b/drivers/clk/ti/mux.c > @@ -160,7 +160,7 @@ static void of_mux_clk_setup(struct device_node *node) > u8 clk_mux_flags = 0; > u32 mask = 0; > u32 shift = 0; > - u32 flags = 0; > + u32 flags = CLK_SET_RATE_NO_REPARENT; > > num_parents = of_clk_get_parent_count(node); > if (num_parents < 2) { > Thanks, queued for 3.16-rc fixes. -Tero