Message-ID: <CAA8EJpoQXe1bHf=EG=6Tt4gWz_4h-rkLHK92_mVQQmZCc4hq4g@mail.gmail.com>
Date:   Mon, 10 Jul 2023 14:40:35 +0300
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Yangtao Li <frank.li@...o.com>
Cc:     "Rafael J. Wysocki" <rafael@...nel.org>,
        Daniel Lezcano <daniel.lezcano@...aro.org>,
        Amit Kucheria <amitk@...nel.org>,
        Zhang Rui <rui.zhang@...el.com>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Thara Gopinath <thara.gopinath@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>,
        Jonathan Cameron <Jonathan.Cameron@...wei.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@...labora.com>,
        linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-arm-msm@...r.kernel.org
Subject: Re: [PATCH v4 06/21] thermal/drivers/db8500: convert to use devm_request*_irq_probe()

On Mon, 10 Jul 2023 at 14:30, Yangtao Li <frank.li@...o.com> wrote:
>
> Hi Dmitry,
>
> On 2023/7/10 19:25, Dmitry Baryshkov wrote:
>
> > On 10/07/2023 12:59, Yangtao Li wrote:
> >> There are more than 700 calls to devm_request_threaded_irq method and
> >> more than 1000 calls to devm_request_irq method. Most drivers only
> >> request one interrupt resource, and these error messages are basically
> >> the same. If error messages are printed everywhere, more than 2000 lines
> >> of code can be saved by removing the msg in the driver.
> >>
> >> And tglx point out that:
> >>
> >>    If we actually look at the call sites of
> >>    devm_request_threaded_irq() then the vast majority of them print
> >> more or
> >>    less lousy error messages. A quick grep/sed/awk/sort/uniq revealed
> >>
> >>       519 messages total (there are probably more)
> >>
> >>       352 unique messages
> >>
> >>       323 unique messages after lower casing
> >>
> >>           Those 323 are mostly just variants of the same patterns with
> >>           slight modifications in formatting and information provided.
> >>
> >>       186 of these messages do not deliver any useful information,
> >>           e.g. "no irq", "
> >>
> >>       The most useful one of all is: "could request wakeup irq: %d"
> >>
> >>    So there is certainly an argument to be made that this particular
> >>    function should print a well formatted and informative error message.
> >>
> >>    It's not a general allocator like kmalloc(). It's specialized and
> >> in the
> >>    vast majority of cases failing to request the interrupt causes the
> >>    device probe to fail. So having proper and consistent information why
> >>    the device cannot be used _is_ useful.
> >>
> >> So convert to use devm_request*_irq_probe() API, which ensure that all
> >> error handling branches print error information.
> >>
> >> In this way, when this function fails, the upper-layer functions can
> >> directly return an error code without missing debugging information.
> >> Otherwise, the error message will be printed redundantly or missing.
> >>
> >> Cc: Thomas Gleixner <tglx@...utronix.de>
> >> Cc: Krzysztof Kozlowski <krzk@...nel.org>
> >> Cc: "Uwe Kleine-König" <u.kleine-koenig@...gutronix.de>
> >> Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> >> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
> >> Signed-off-by: Yangtao Li <frank.li@...o.com>
> >> ---
> >>   drivers/thermal/db8500_thermal.c | 16 ++++++----------
> >>   drivers/thermal/qcom/lmh.c       |  7 +++----
> >
> > Please split LMH to a separate driver.
>
>
> Sorry for mixing these two patches together,
>
> can I add your Reviewed-by tag when the patch is resubmitted for the
> next version?

Yes, please add it to the LMH patch.

>
>
> Thx,
>
> Yangtao
>
> >
> >>   2 files changed, 9 insertions(+), 14 deletions(-)
> >>
> >> diff --git a/drivers/thermal/db8500_thermal.c
> >> b/drivers/thermal/db8500_thermal.c
> >> index fca5c2c93bf9..0ef8fc2eb4a1 100644
> >> --- a/drivers/thermal/db8500_thermal.c
> >> +++ b/drivers/thermal/db8500_thermal.c
> >> @@ -164,25 +164,21 @@ static int db8500_thermal_probe(struct
> >> platform_device *pdev)
> >>       if (low_irq < 0)
> >>           return low_irq;
> >>   -    ret = devm_request_threaded_irq(dev, low_irq, NULL,
> >> +    ret = devm_request_threaded_irq_probe(dev, low_irq, NULL,
> >>           prcmu_low_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
> >> -        "dbx500_temp_low", th);
> >> -    if (ret < 0) {
> >> -        dev_err(dev, "failed to allocate temp low irq\n");
> >> +        "dbx500_temp_low", th, "temp low");
> >> +    if (ret < 0)
> >>           return ret;
> >> -    }
> >>         high_irq = platform_get_irq_byname(pdev, "IRQ_HOTMON_HIGH");
> >>       if (high_irq < 0)
> >>           return high_irq;
> >>   -    ret = devm_request_threaded_irq(dev, high_irq, NULL,
> >> +    ret = devm_request_threaded_irq_probe(dev, high_irq, NULL,
> >>           prcmu_high_irq_handler, IRQF_NO_SUSPEND | IRQF_ONESHOT,
> >> -        "dbx500_temp_high", th);
> >> -    if (ret < 0) {
> >> -        dev_err(dev, "failed to allocate temp high irq\n");
> >> +        "dbx500_temp_high", th, "temp high");
> >> +    if (ret < 0)
> >>           return ret;
> >> -    }
> >>         /* register of thermal sensor and get info from DT */
> >>       th->tz = devm_thermal_of_zone_register(dev, 0, th, &thdev_ops);
> >> diff --git a/drivers/thermal/qcom/lmh.c b/drivers/thermal/qcom/lmh.c
> >> index f6edb12ec004..48a14d7e8bf5 100644
> >> --- a/drivers/thermal/qcom/lmh.c
> >> +++ b/drivers/thermal/qcom/lmh.c
> >> @@ -207,11 +207,10 @@ static int lmh_probe(struct platform_device *pdev)
> >>         /* Disable the irq and let cpufreq enable it when ready to
> >> handle the interrupt */
> >>       irq_set_status_flags(lmh_data->irq, IRQ_NOAUTOEN);
> >> -    ret = devm_request_irq(dev, lmh_data->irq, lmh_handle_irq,
> >> -                   IRQF_ONESHOT | IRQF_NO_SUSPEND,
> >> -                   "lmh-irq", lmh_data);
> >> +    ret = devm_request_irq_probe(dev, lmh_data->irq, lmh_handle_irq,
> >> +                     IRQF_ONESHOT | IRQF_NO_SUSPEND,
> >> +                     "lmh-irq", lmh_data, NULL);
> >>       if (ret) {
> >> -        dev_err(dev, "Error %d registering irq %x\n", ret,
> >> lmh_data->irq);
> >>           irq_domain_remove(lmh_data->domain);
> >>           return ret;
> >>       }
> >



-- 
With best wishes
Dmitry

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