[PATCH] coresight: etm4x: Don't bother the user with nonessential log message

[Suzuki K Poulose]

On 03/08/2023 10:08, James Clark wrote:
> 
> 
> On 03/08/2023 07:22, Tian Tao wrote:
>> Each cpu will print the following log when initializing
>> ETM "coresight etm1: CPU1: etm v4.5 initialized", if there are a lot
>> of cpus, e.g. 128. there will be a screen full of this log. replace
>> dev_info with dev_dbg prints only when needed.
>>
>> Signed-off-by: Tian Tao <tiantao6 at hisilicon.com>
>> ---
>>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index 7e307022303a..7b51e8594fd5 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -2033,7 +2033,7 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
>>   
>>   	etmdrvdata[drvdata->cpu] = drvdata;
>>   
>> -	dev_info(&drvdata->csdev->dev, "CPU%d: %s v%d.%d initialized\n",
>> +	dev_dbg(&drvdata->csdev->dev, "CPU%d: %s v%d.%d initialized\n",
>>   		 drvdata->cpu, type_name, major, minor);
>>   
>>   	if (boot_enable) {
> 
> Hi Tian,
> 
> Do you think it's worth keeping a single info printout as well as the
> per-cpu dbg one? I'm thinking that the only way to get these messages
> now is to boot with debug printing on, and that is quite noisy. Because
> it's too late to use debugfs to enable just coresight debug messages
> after booting. So something like this:
> 
>    dev_info_once(&drvdata->csdev->dev, "%s v%d.%d initialized\n",

I would rather remove all of this. One can always check the devices
at /sys/bus/coresight/devices/etmX.

> 
> Also I still get this printed out per-cpu, which is from
> coresight-syscfg.c. Do you not see this? Might be worth doing the same
> change there.
> 
>    CSCFG registered etm0
>    CSCFG registered etm1
>    CSCFG registered etm2
>    CSCFG registered etm3

+1, Please make them debug


Suzuki