From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bo Shen Subject: Re: [PATCH v4] PWM: atmel-pwm: add PWM controller driver Date: Sun, 29 Sep 2013 18:02:37 +0800 Message-ID: <5247FABD.9070405@atmel.com> References: <1380079664-21959-1-git-send-email-voice.shen@atmel.com> <5245B7D7.2040405@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5245B7D7.2040405-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Alexandre Belloni Cc: Thierry Reding , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-pwm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, plagnioj-sclMFOaUSTBWk0Htik3J/w@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Alexandre, On 9/28/2013 00:52, Alexandre Belloni wrote: [snip] >> +static int atmel_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) >> +{ >> + struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); >> + int ret; >> + >> + ret = clk_enable(atmel_pwm->clk); >> + if (ret) { >> + pr_err("failed to enable pwm clock\n"); >> + return ret; >> + } >> + > > This will increment clk->enable_count each time it is called. Yes, that's true. >> + atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm); >> + >> + return 0; >> +} >> + >> +static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) >> +{ >> + struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); >> + u32 val; >> + >> + atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm); >> + >> + val = atmel_pwm_readl(atmel_pwm, PWM_SR); >> + if ((val & PWM_SR_ALL_CH_ON) == 0) >> + clk_disable(atmel_pwm->clk); >> +} > > This will decrement clk->enable_count only once there are no pwm enabled > anymore. So in you enable more than one channel, you will never disable > the clock. The simple fix is to always call clk_diasble, regardless of > the state of the other channels. Thank for point out this. I see you have sent out a patch to fix it (however the other contents of your patch doesn't work). So, do you prefer I send out v5 patch to fix this? or you fix your patch at same time fix this issue? Best Regards, Bo Shen -- 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