Re: [PATCH] Declare the file_operations struct as const

From: Krish Jain <krishjain02939@gmail.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Bryan Brattlof <hello@bryanbrattlof.com>,
	"Fabio M. De Francesco" <fmdefrancesco@gmail.com>,
	linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Declare the file_operations struct as const
Date: Wed, 1 Sep 2021 17:34:36 +0200	[thread overview]
Message-ID: <CAPGkw+z+uepM0hiNh48xjjD7=2rpgr+RSLzMcHbw2iE=8y+xqQ@mail.gmail.com> (raw)
In-Reply-To: <YS+cexhuqldPaACs@kroah.com>

On Wed, Sep 1, 2021 at 5:30 PM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Wed, Sep 01, 2021 at 05:20:13PM +0200, Krish Jain wrote:
> > On Wed, Sep 1, 2021 at 1:00 AM Bryan Brattlof <hello@bryanbrattlof.com> wrote:
> > >
> > > On this day, August 31, 2021, thus sayeth Fabio M. De Francesco:
> > > >
> > > > I just want to *really* thank you for the hard work you got involved and that
> > > > you carried out with one of the highest levels of professionalism (and
> > > > patience :)) very few of us could ever equal (not I, for sure).
> > > >
> > > > I thank you also not for the technical hints you gave to Krish, instead for
> > > > your your choice "to not rob [you] Krish the opportunity to learn".
> > > >
> > > > Actually I was tempted to write something like "first do this, than that, and
> > > > finally run this tool". But I was able to desist, by learning from you how
> > > > people should be helped for real.
> > > >
> > > > Most of us here should learn by your attitude.
> > > >
> > > > Thanks again, seriously.
> > > >
> > >
> > > Thank you for such kind words, Fabio.
> > >
> > > I was very lucky to be, and still am, surrounded by people who
> > > demonstrated this idea to me when I was young. I am very happy to see
> > > others here see how beneficial and helpful (in the long term) learning
> > > this way can be.
> > >
> > > I'm grateful to have found and be a part of this community.
> > > ~Bryan
> > >
> >
> >
> >
> > Interesting.
> >
> > "make drivers/staging/android/ " works now (finally!) and shows me the
> > errors when I mess up in the file  ashmem.c for example.
> > Furthermore, " make CCFLAGS=-Werror W=1 drivers/staging/android/    "
> > outputs the same errors too just more verbose. So it works completely
> > now, However, "make CCFLAGS=-Werror W=1 M=drivers/staging/android/
> > " just takes to new prompt line and does not output anything. Do you
> > know why?
>
> "M=pathname" is different than "pathname", you are asking for different
> things to happen here, so depending on your kernel configuration,
> different things will be built (or not built).
>
> And don't mes with CCFLAGS settings for building the kernel unless you
> _really_ know what you are doing.  For staging tree work, it's not
> advised at all.
>
> good luck!
>
> greg k-h

Oh ok, thanks Greg. I only attempted to use "make CCFLAGS=-Werror W=1
M=drivers/staging/android/" as that's the command Bryan used earlier
and it worked.

"As for your patch, I built the driver using:

  $ make CCFLAGS=-Werror W=1 M=drivers/staging/android"

Can you tell me why this is the case? And whether I can just start
working on an android driver patch and testing whether the android
driver builds successfully using "make drivers/staging/android/ "
instead of that command, would it be the same effectively?

Best Regards,

Thanks so much for helping a high schooler learn his way around the kernel