linux-kernel - RE: [PATCH] cpufreq: imx6q: Disable only available frequencies

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Message-ID: <a7bfc85a9b664daf84e90adf520c0a56@dh-electronics.com>
Date:   Thu, 11 May 2023 14:38:42 +0000
From:   Christoph Niedermaier <cniedermaier@...electronics.com>
To:     Viresh Kumar <viresh.kumar@...aro.org>
CC:     "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Shawn Guo <shawnguo@...nel.org>, Marek Vasut <marex@...x.de>,
        Fabio Estevam <festevam@...x.de>,
        NXP Linux Team <linux-imx@....com>,
        "open list:CPU FREQUENCY SCALING FRAMEWORK" 
        <linux-pm@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] cpufreq: imx6q: Disable only available frequencies

From: Viresh Kumar [mailto:viresh.kumar@...aro.org]
Sent: Thursday, May 11, 2023 11:54 AM
> On 11-05-23, 11:23, Christoph Niedermaier wrote:
>> @@ -254,16 +269,16 @@ static int imx6q_opp_check_speed_grading(struct device *dev)
>>       val &= 0x3;
>>
>>       if (val < OCOTP_CFG3_SPEED_996MHZ)
>> -             if (dev_pm_opp_disable(dev, 996000000))
>> +             if (disable_freq_if_available(dev, 996000000))
>>                       dev_warn(dev, "failed to disable 996MHz OPP\n");
> 
> Ahh, these warnings.
> 
> What about printing the warning only when returned error != -ENODEV ?
> Or just marking them dev_dbg() ?

I have kept to the documentation of opp, but if -ENODEV is possible
I prefer it. My suggestion is to change each "dev_pm_opp_disable" in
this way:

-	if (val < OCOTP_CFG3_SPEED_996MHZ)
-		if (dev_pm_opp_disable(dev, 996000000))
+	if (val < OCOTP_CFG3_SPEED_996MHZ) {
+		ret_opp = dev_pm_opp_disable(dev, 996000000);
+		if (ret_opp < 0 && ret_opp != -ENODEV)
 			dev_warn(dev, "failed to disable 996MHz OPP\n");
+	}

If that's OK, I can do a version 2 with it.


Regards
Christoph