From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 15 Jul 2015 16:48:23 -0700 From: Stephen Boyd To: Gabriel Fernandez Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , Russell King , Michael Turquette , Peter Griffin , Pankaj Dev , Olivier Bideau , Geert Uytterhoeven , Fabian Frederick , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel@stlinux.com, linux-clk@vger.kernel.org Subject: Re: [PATCH 1/3] drivers: clk: st: Support for enable/disable in Clockgen PLLs Message-ID: <20150715234823.GT30412@codeaurora.org> References: <1436443060-12866-1-git-send-email-gabriel.fernandez@linaro.org> <1436443060-12866-2-git-send-email-gabriel.fernandez@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1436443060-12866-2-git-send-email-gabriel.fernandez@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: On 07/09, Gabriel Fernandez wrote: > @@ -270,6 +285,73 @@ static int clkgen_pll_is_enabled(struct clk_hw *hw) > return !poweroff; > } > > +static int __clkgen_pll_enable(struct clk_hw *hw) > +{ > + struct clkgen_pll *pll = to_clkgen_pll(hw); > + unsigned long timeout; > + int ret = 0; > + > + if (clkgen_pll_is_enabled(hw)) > + return 0; > + > + CLKGEN_WRITE(pll, pdn_ctrl, 0); > + > + timeout = jiffies + msecs_to_jiffies(10); Jiffies isn't guaranteed to increment here because .enable/.disable is called with irqs disabled and if this is the only CPU running it won't be getting interrupts to update jiffies. > + > + while (!clkgen_pll_is_locked(hw)) { > + if (time_after(jiffies, timeout)) > + return -ETIMEDOUT; > + cpu_relax(); > + } > + > + pr_debug("%s:%s enabled\n", __clk_get_name(hw->clk), __func__); > + > + return ret; > +} -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project From mboxrd@z Thu Jan 1 00:00:00 1970 From: sboyd@codeaurora.org (Stephen Boyd) Date: Wed, 15 Jul 2015 16:48:23 -0700 Subject: [PATCH 1/3] drivers: clk: st: Support for enable/disable in Clockgen PLLs In-Reply-To: <1436443060-12866-2-git-send-email-gabriel.fernandez@linaro.org> References: <1436443060-12866-1-git-send-email-gabriel.fernandez@linaro.org> <1436443060-12866-2-git-send-email-gabriel.fernandez@linaro.org> Message-ID: <20150715234823.GT30412@codeaurora.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/09, Gabriel Fernandez wrote: > @@ -270,6 +285,73 @@ static int clkgen_pll_is_enabled(struct clk_hw *hw) > return !poweroff; > } > > +static int __clkgen_pll_enable(struct clk_hw *hw) > +{ > + struct clkgen_pll *pll = to_clkgen_pll(hw); > + unsigned long timeout; > + int ret = 0; > + > + if (clkgen_pll_is_enabled(hw)) > + return 0; > + > + CLKGEN_WRITE(pll, pdn_ctrl, 0); > + > + timeout = jiffies + msecs_to_jiffies(10); Jiffies isn't guaranteed to increment here because .enable/.disable is called with irqs disabled and if this is the only CPU running it won't be getting interrupts to update jiffies. > + > + while (!clkgen_pll_is_locked(hw)) { > + if (time_after(jiffies, timeout)) > + return -ETIMEDOUT; > + cpu_relax(); > + } > + > + pr_debug("%s:%s enabled\n", __clk_get_name(hw->clk), __func__); > + > + return ret; > +} -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Boyd Subject: Re: [PATCH 1/3] drivers: clk: st: Support for enable/disable in Clockgen PLLs Date: Wed, 15 Jul 2015 16:48:23 -0700 Message-ID: <20150715234823.GT30412@codeaurora.org> References: <1436443060-12866-1-git-send-email-gabriel.fernandez@linaro.org> <1436443060-12866-2-git-send-email-gabriel.fernandez@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1436443060-12866-2-git-send-email-gabriel.fernandez-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Gabriel Fernandez Cc: Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Srinivas Kandagatla , Maxime Coquelin , Patrice Chotard , Russell King , Michael Turquette , Peter Griffin , Pankaj Dev , Olivier Bideau , Geert Uytterhoeven , Fabian Frederick , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, kernel-F5mvAk5X5gdBDgjK7y7TUQ@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On 07/09, Gabriel Fernandez wrote: > @@ -270,6 +285,73 @@ static int clkgen_pll_is_enabled(struct clk_hw *hw) > return !poweroff; > } > > +static int __clkgen_pll_enable(struct clk_hw *hw) > +{ > + struct clkgen_pll *pll = to_clkgen_pll(hw); > + unsigned long timeout; > + int ret = 0; > + > + if (clkgen_pll_is_enabled(hw)) > + return 0; > + > + CLKGEN_WRITE(pll, pdn_ctrl, 0); > + > + timeout = jiffies + msecs_to_jiffies(10); Jiffies isn't guaranteed to increment here because .enable/.disable is called with irqs disabled and if this is the only CPU running it won't be getting interrupts to update jiffies. > + > + while (!clkgen_pll_is_locked(hw)) { > + if (time_after(jiffies, timeout)) > + return -ETIMEDOUT; > + cpu_relax(); > + } > + > + pr_debug("%s:%s enabled\n", __clk_get_name(hw->clk), __func__); > + > + return ret; > +} -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html