From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajendra Nayak Subject: Re: [PATCH 04/29] ARM: omap: clk: use clk_prepare_enable and clk_disable_unprepare Date: Fri, 15 Jun 2012 10:26:26 +0530 Message-ID: <4FDAC07A.7020702@ti.com> References: <1339678038-23082-1-git-send-email-rnayak@ti.com> <1339678038-23082-5-git-send-email-rnayak@ti.com> <20120614191147.GP19410@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from na3sys009aog128.obsmtp.com ([74.125.149.141]:42083 "EHLO na3sys009aog128.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751034Ab2FOE4e (ORCPT ); Fri, 15 Jun 2012 00:56:34 -0400 Received: by obbef5 with SMTP id ef5so4925737obb.21 for ; Thu, 14 Jun 2012 21:56:32 -0700 (PDT) In-Reply-To: <20120614191147.GP19410@gmail.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Mike Turquette Cc: paul@pwsan.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org On Friday 15 June 2012 12:41 AM, Mike Turquette wrote: > On 20120614-18:16, Rajendra Nayak wrote: >> As we move to Common clk framework use clk_prepare_enable() >> instead of clk_enable() and similarly clk_disable_unprepare() >> instead of clk_disable() >> >> Based on initial changes from Mike turquette. >> >> Signed-off-by: Rajendra Nayak > > Hi Rajendra, > > This change looks good except for two questions I have below, related to > calling prepare in an interrupt context. If those are non-issues then > please add my: > > Acked-by: Mike Turquette > > (or my Reviewed-by... I can never remember which one is correct) > > snip > >> diff --git a/arch/arm/mach-omap2/display.c b/arch/arm/mach-omap2/display.c >> index 5fb47a1..e5f8e48 100644 >> --- a/arch/arm/mach-omap2/display.c >> +++ b/arch/arm/mach-omap2/display.c >> @@ -471,7 +471,7 @@ int omap_dss_reset(struct omap_hwmod *oh) >> >> for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i> 0; i--, oc++) >> if (oc->_clk) >> - clk_enable(oc->_clk); >> + clk_prepare_enable(oc->_clk); >> >> dispc_disable_outputs(); >> >> @@ -498,7 +498,7 @@ int omap_dss_reset(struct omap_hwmod *oh) >> >> for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i> 0; i--, oc++) >> if (oc->_clk) >> - clk_disable(oc->_clk); >> + clk_disable_unprepare(oc->_clk); >> >> r = (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0; >> > > omap_dss_reset gets used by hwmod/omap_device, right? Does the reset > path ever get called in an interrupt context? If so clk_prepare might > sleep, which is bad. right, I completely missed this. Will take a look at these and others too. thanks. regards, Rajendra > > snip > >> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c >> index bf86f7e..b46ae17 100644 >> --- a/arch/arm/mach-omap2/omap_hwmod.c >> +++ b/arch/arm/mach-omap2/omap_hwmod.c >> @@ -693,7 +693,7 @@ static int _enable_clocks(struct omap_hwmod *oh) >> pr_debug("omap_hwmod: %s: enabling clocks\n", oh->name); >> >> if (oh->_clk) >> - clk_enable(oh->_clk); >> + clk_prepare_enable(oh->_clk); >> > > The same question above applies to basically all of the hwmod function > changes below. I don't know if runtime pm invokes these in an interrupt > context or not, but it is something to think about. > > Regards, > Mike