Re: Kernelnewbies Digest, Vol 71, Issue 22

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Hi Wenda Ni,

Please go through the following link to enable debugging output.Seems you have missed enabling DEBUG in Makefile. Hope it will help you.

https://www.kernel.org/doc/local/pr_debug.txt

CFLAGS_[filename].o := -DDEBUG




With Best Regards,

Sukanya Ch

Software Engineer

VVDN Technologies Pvt Ltd

Cell : +91 9551955031 | Skype : sukanya.chinthamreddy

 

On Tue, Oct 18, 2016 at 7:44 PM, <kernelnewbies-request@xxxxxxxxxxxxxxxxx> wrote:
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Today's Topics:

   1. kernel loglevel (Wenda Ni)
   2. Re: kernel loglevel (Wenda Ni)
   3. Re: kernel loglevel (Joel Fernandes)
   4. Re: kernel loglevel (Thibaut SAUTEREAU)
   5. Re: kernel loglevel (Wenda Ni)
   6. Fw: TPS65910 Regulator Isuue (Amit Mahadik)


----------------------------------------------------------------------

Message: 1
Date: Mon, 17 Oct 2016 19:17:32 -0400
From: Wenda Ni <wonda.ni@xxxxxxxxx>
Subject: kernel loglevel
To: kernelnewbies@kernelnewbies.org
Message-ID:
        <CAEnvTt0RRDWtMD=VxVpuhiiJ+MRX2g3WiTgXkA-M5GGaTMyB-g@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8

Dear all,

I am working on a kernel module that incorporate both pr_debug and
pr_warn. I would like to see pr_debug messages from dmesg.

What I followed is to specify kernel parameter by saying "loglevel=7".
This can be seen confirmed  from /proc/cmdline. But still, I donot get
pr_debug level messages either from dmesg or from /var/log/messages. I
also tried echo 7 > /proc/sys/kernel/printk. It does not return what I
expect, either.

Let me know what I am missing. Thank you very much in advance.

Cheers,

Wenda Ni, Ph.D.



------------------------------

Message: 2
Date: Mon, 17 Oct 2016 19:47:14 -0400
From: Wenda Ni <wonda.ni@xxxxxxxxx>
Subject: Re: kernel loglevel
To: Thibaut SAUTEREAU <thibaut.sautereau@telecom-sudparis.eu>
Cc: kernelnewbies@kernelnewbies.org
Message-ID:
        <CAEnvTt3oh+tuhKCwho8eZd5VmJfuXdcmWGpUpsjiH2wWSFpWvg@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset="utf-8"

Thank you so much, Thibaut. I have spotted the source-code logic in
include/linux/prink.h

Cheers,

Wenda Ni, Ph.D.



On Mon, Oct 17, 2016 at 7:41 PM, Thibaut SAUTEREAU <
thibaut.sautereau@telecom-sudparis.eu> wrote:
> On Mon, Oct 17, 2016 at 07:17:32PM -0400, Wenda Ni wrote:
>> Dear all,
>>
>> I am working on a kernel module that incorporate both pr_debug and
>> pr_warn. I would like to see pr_debug messages from dmesg.
>>
>> What I followed is to specify kernel parameter by saying "loglevel=7".
>> This can be seen confirmed  from /proc/cmdline. But still, I donot get
>> pr_debug level messages either from dmesg or from /var/log/messages. I
>> also tried echo 7 > /proc/sys/kernel/printk. It does not return what I
>> expect, either.
>>
>> Let me know what I am missing. Thank you very much in advance.
>>
>> Cheers,
>>
>> Wenda Ni, Ph.D.
>>
>> _______________________________________________
>> Kernelnewbies mailing list
>> Kernelnewbies@kernelnewbies.org
>> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
> Hello Wenda,
>
> I encountered the same issue a while ago.
> As stated here: http://elinux.org/Debugging_by_printing
> pr_debug is replaced with an empty statement unless the kernel is compiled
> with DEBUG. So if you just want to play with printing kernel debug logs,
> just define the DEBUG macro in your module source file for testing.
>
> I also observed that without a new line character at the end of the string
> passed to pr_debug, I could not find the log line in dmesg output. Not
sure
> where this comes from.
>
> --
> Thibaut SAUTEREAU
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Message: 3
Date: Mon, 17 Oct 2016 16:48:46 -0700
From: Joel Fernandes <agnel.joel@xxxxxxxxx>
Subject: Re: kernel loglevel
To: Wenda Ni <wonda.ni@xxxxxxxxx>
Cc: "kernelnewbies@kernelnewbies.org"
        <kernelnewbies@kernelnewbies.org>
Message-ID:
        <CAD=GYpb-UKodnqeb0o71KytF_M2pLGV7bRzZ3YL4Ck0GqLdU+A@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8

Hi Wenda,

pr_debug needs you to define the DEBUG macro to activate it.

Check:
http://stackoverflow.com/questions/28936199/pr-debug-not-giving-any-output

and the kernel docs,
https://www.kernel.org/doc/local/pr_debug.txt

Joel

On Mon, Oct 17, 2016 at 4:17 PM, Wenda Ni <wonda.ni@xxxxxxxxx> wrote:
> Dear all,
>
> I am working on a kernel module that incorporate both pr_debug and
> pr_warn. I would like to see pr_debug messages from dmesg.
>
> What I followed is to specify kernel parameter by saying "loglevel=7".
> This can be seen confirmed  from /proc/cmdline. But still, I donot get
> pr_debug level messages either from dmesg or from /var/log/messages. I
> also tried echo 7 > /proc/sys/kernel/printk. It does not return what I
> expect, either.
>
> Let me know what I am missing. Thank you very much in advance.
>
> Cheers,
>
> Wenda Ni, Ph.D.
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies



------------------------------

Message: 4
Date: Tue, 18 Oct 2016 01:41:57 +0200
From: Thibaut SAUTEREAU <thibaut.sautereau@telecom-sudparis.eu>
Subject: Re: kernel loglevel
To: Wenda Ni <wonda.ni@xxxxxxxxx>
Cc: kernelnewbies@kernelnewbies.org
Message-ID: <20161017234156.GB1191@mines-telecom.fr>
Content-Type: text/plain; charset="utf-8"

On Mon, Oct 17, 2016 at 07:17:32PM -0400, Wenda Ni wrote:
> Dear all,
>
> I am working on a kernel module that incorporate both pr_debug and
> pr_warn. I would like to see pr_debug messages from dmesg.
>
> What I followed is to specify kernel parameter by saying "loglevel=7".
> This can be seen confirmed  from /proc/cmdline. But still, I donot get
> pr_debug level messages either from dmesg or from /var/log/messages. I
> also tried echo 7 > /proc/sys/kernel/printk. It does not return what I
> expect, either.
>
> Let me know what I am missing. Thank you very much in advance.
>
> Cheers,
>
> Wenda Ni, Ph.D.
>
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies@kernelnewbies.org
> https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

Hello Wenda,

I encountered the same issue a while ago.
As stated here: http://elinux.org/Debugging_by_printing
pr_debug is replaced with an empty statement unless the kernel is compiled
with DEBUG. So if you just want to play with printing kernel debug logs,
just define the DEBUG macro in your module source file for testing.

I also observed that without a new line character at the end of the string
passed to pr_debug, I could not find the log line in dmesg output. Not sure
where this comes from.

--
Thibaut SAUTEREAU
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Message: 5
Date: Mon, 17 Oct 2016 20:29:33 -0400
From: Wenda Ni <wonda.ni@xxxxxxxxx>
Subject: Re: kernel loglevel
To: Joel Fernandes <agnel.joel@xxxxxxxxx>
Cc: "kernelnewbies@kernelnewbies.org"
        <kernelnewbies@kernelnewbies.org>
Message-ID:
        <CAEnvTt0BmAJ_nxf0oEUsFqqJjGssuXCQBg6pdt95Jk3PyBBQew@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset="utf-8"

Hi Joel,

It works by specifying ccflags-y += -DDEBUG in the Makefile.

Thank you for the info!!!!


Cheers,

Wenda Ni, Ph.D.


On Mon, Oct 17, 2016 at 7:48 PM, Joel Fernandes <agnel.joel@xxxxxxxxx>
wrote:

> Hi Wenda,
>
> pr_debug needs you to define the DEBUG macro to activate it.
>
> Check:
> http://stackoverflow.com/questions/28936199/pr-debug-not-giving-any-output
>
> and the kernel docs,
> https://www.kernel.org/doc/local/pr_debug.txt
>
> Joel
>
> On Mon, Oct 17, 2016 at 4:17 PM, Wenda Ni <wonda.ni@xxxxxxxxx> wrote:
> > Dear all,
> >
> > I am working on a kernel module that incorporate both pr_debug and
> > pr_warn. I would like to see pr_debug messages from dmesg.
> >
> > What I followed is to specify kernel parameter by saying "loglevel=7".
> > This can be seen confirmed  from /proc/cmdline. But still, I donot get
> > pr_debug level messages either from dmesg or from /var/log/messages. I
> > also tried echo 7 > /proc/sys/kernel/printk. It does not return what I
> > expect, either.
> >
> > Let me know what I am missing. Thank you very much in advance.
> >
> > Cheers,
> >
> > Wenda Ni, Ph.D.
> >
> > _______________________________________________
> > Kernelnewbies mailing list
> > Kernelnewbies@kernelnewbies.org
> > https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
>
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Message: 6
Date: Tue, 18 Oct 2016 14:11:41 +0000 (UTC)
From: Amit Mahadik <amitmahadik35@xxxxxxxxx>
Subject: Fw: TPS65910 Regulator Isuue
To: Kernelnewbies <kernelnewbies@kernelnewbies.org>
Message-ID: <1865063607.2350837.1476799901899@xxxxxxxxxxxxxx>
Content-Type: text/plain; charset="utf-8"




Hi,? ? ?I am working on integrating TPS695190 regulator code into kernel version 4.4.16. The regulator powers MMC card slot using Designware MMC controller. I have declared the necessary code in my board.c file. The MMC card slot is powered by ldo8 supply declared as
-----------------------------------------------------------------------------Code---------------------------------------------------------------------------------

static struct regulator_consumer_supply opv5xc_ldo8_supply[] = {
??????? REGULATOR_SUPPLY("sd_vdd", NULL),
};

static struct regulator_init_data opv5xc_ldo8 = {
??????? .constraints = {
??????????????? .min_uV = 1000000,
??????????????? .max_uV = 3300000,
??????????????? .valid_ops_mask = (REGULATOR_CHANGE_VOLTAGE |
??????????????????????????????? REGULATOR_CHANGE_STATUS),
??????????????? .boot_on = 1,
??????? },
??????? .num_consumer_supplies = ARRAY_SIZE(opv5xc_ldo8_supply),
??????? .consumer_supplies = opv5xc_ldo8_supply,
};
static struct tps65910_board tps65910_pdata = {
????? ??????? .tps65910_pmic_init_data[TPS65911_REG_LDO8]???? = &opv5xc_ldo8,
};
static struct i2c_board_info __initdata opv5xc_i2c1_devs[] = {
??????? {
??????????????? I2C_BOARD_INFO ("tps65911", TPS65910_I2C_ID1),
??????????????? .platform_data = &tps65910_pdata,
??????? },
};
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
When I call regulator_get struct regulator *sd_vdd = regulator_get(NULL, "sd_vdd");? function from the Designware MMC driver code function the kernel panics.I have attached the log file for reference. Can somebody please let me know what I am doing wrong here?
Regards,Amit.



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