Re: [PATCH v4 06/21] thermal/drivers/db8500: convert to use devm_request*_irq_probe()

[Yangtao Li <frank.li@vivo.com>]

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@linutronix.de>
>> Cc: Krzysztof Kozlowski <krzk@kernel.org>
>> Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
>> Cc: Jonathan Cameron <Jonathan.Cameron@Huawei.com>
>> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
>> Signed-off-by: Yangtao Li <frank.li@vivo.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?


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;
>>       }
>