From:   "Fabio M. De Francesco" <fmdefrancesco@gmail.com>
To:     Khadija Kamran <kamrankhadijadj@gmail.com>
Cc:     outreachy@lists.linux.dev,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5] staging: axis-fifo: initialize timeouts in probe only
Date:   Thu, 16 Mar 2023 21:07:09 +0100
Message-ID: <2599595.k3LOHGUjKi@suse>
In-Reply-To: <ZBNhXc3sVVLdibUF@khadija-virtual-machine>
References: <ZBMR4s8xyHGqMm72@khadija-virtual-machine> <2162728.C4sosBPzcN@suse>
 <ZBNhXc3sVVLdibUF@khadija-virtual-machine>
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On gioved=EC 16 marzo 2023 19:35:09 CET Khadija Kamran wrote:
> On Thu, Mar 16, 2023 at 05:17:47PM +0100, Fabio M. De Francesco wrote:
> > On gioved=EC 16 marzo 2023 16:09:08 CET Khadija Kamran wrote:

[snip]

> Hey Fabio!
>=20
> Hope you are doing well. After  spending a lot of time on this I am
> stuck now. Kindly help me resolve this issue or understand it better.
>=20
> Following your instructions I deleted my config file and copied one from
> the /boot/ directory. After that I enabled the dependencies(CONFIG_OF=3Dy
> and CONFIG_HAS_IOMEM=3Dy). I was successfully able to enable axis-fifo as
> a module.
>=20
> I then ran the following commands:
>  - make drivers/staging/axis-fifo/

No, this is not the right command... you are not invoking the linker to mak=
e=20
the .ko object.

Use "make M=3Ddrivers/staging/axis-fifo/"
or "make M=3Ddrivers/staging/axis-fifo/ W=3D1 -j8" (the latter to enable le=
vel '1'=20
warning and run on your 2 * 4 logical cores).

>  - sudo make modules_install install(this command took hours) :'(

This is odd, it shouldn't :-/

As I said in another message, I'll set aside some time to help you check if=
=20
you need to fine tune your VM and Hypervisor configuration.=20

I'm returning on the same subject we have been talked about because you sai=
d=20
at least twice that your builds and install are too slow. We'll try to=20
diagnose it in an IRC session on #kernel-outreachy (I'm pretty sure for the=
=20
first days of next week - I'll send an invite).

> > When you are done with build, install, and final reboot to test if your
> > module can "modprobe" or "insmod" (i.e. link with the running custom=20
kernel
> > you built, installed and boot), try to compare the output of the follow=
ing
> > commands:
> >=20
> > # uname -a
> > Linux suse 6.2.2-1-default #1 SMP PREEMPT_DYNAMIC Thu Mar  9 06:06:13 U=
TC
> > 2023 (44ca817) x86_64 x86_64 x86_64 GNU/Linux
>=20
> The above command works
>=20
> > AND
> >=20
> > # modinfo <name of the module you are testing here>
>=20
> On running 'modinfo axis-fifo' I get error saying module axis-fifo not
> found.

Try again after building with "M=3Ddrivers/staging" (as said above). Don't=
=20
forget to run "make modules_install install" and then reboot into your cust=
om=20
built Kernel, not the distribution's kernel.

While you are there, run "lsmod" to see all loaded modules. Pick one random=
ly=20
from the output list and run "modinfo name_of_the_module_you_want_info_abou=
t".
=20
> > I'm running "modinfo kvm" (but showing only two of many lines):
> >=20
> > # modinfo kvm
> > filename:       /lib/modules/6.2.2-1-default/kernel/arch/x86/kvm/
kvm.ko.zst
> > vermagic:       6.2.2-1-default SMP preempt mod_unload modversions
> >=20
> > Can you see that the kernel in "uname -a" and the filename and vermagic=
=20
have
> > the same "6.2.2-1-default"? Well, so I'm sure I'm running the right Ker=
nel
> > and inserted the appropriate "kvm" module.
> >=20
> > Furthermore, before rebooting your custom kernel, you may also look at =
the
> > directory in the Kernel where you compiled your module and search for=20
"*.o"
> > "*mod*" and "*.ko" files. If you have them, you built your module=20
properly.
>=20
> There is a "*.o" file and "*.mod" file but there is no "*.ko" file in
> the axis-fifo directory.
>=20
> Kindly help me with this.
>=20
> Regards,
> Khadija
>=20
> > Thanks,
> >=20
> > Fabio

Let me know if this time it works.

=46abio

P.S.: Have you had time to read that "Linux Kernel Module Programming" guid=
e I=20
sent you the link of? You can find a lot of information about modules there=
=2E=20
I'd strongly recommend you to read it.=20