[gentoo-user] Floppy disk support removed from kernel 3.4.9.

[gentoo-user] Floppy disk support removed from kernel 3.4.9.

[Alan Mackenzie]

Hi, Everybody!

Floppy disk support has been removed from kernel 3.4.9.  I'm not very
happy about this.  Does anybody know why, or by whom?

This removal has been done in a somewhat peculiar manner.  The config
option was called CONFIG_BLK_DEV_FD, and used to be at <Device
Drivers>/<Block Devices>.  It is now not visible there.  

However, Typing '/' BLK_DEV_FD in 'make menuconfig' returns its
documentation, saying BLK_DEV_FD is dependent upon
CONFIG_ARCH_MAY_HAVE_PC_FDC.  This latter variable isn't visible
anywhere.

I tried setting ARCH_MAY_HAVE_PC_FDC by hand in .config, but that didn't
help.  'make menuconfig' just unset it again of its own accord.  Then I
inserted BLK_DEV_FD into .config by hand and built the kernel.  I haven't
tested it yet.

All this seems rather strange.  Why shouldn't I be able to use my floppy
drive?

-- 
Alan Mackenzie (Nuremberg, Germany).

Re: [gentoo-user] Floppy disk support removed from kernel 3.4.9.

[Canek Peláez Valdés]

On Sun, Oct 28, 2012 at 11:48 AM, Alan Mackenzie <acm@muc.de> wrote:
> Hi, Everybody!
>
> Floppy disk support has been removed from kernel 3.4.9.  I'm not very
> happy about this.  Does anybody know why, or by whom?

Nobody removed anything; it's still there, in 3.6.3. I'm not using it,
but I can select it without problems.

> This removal has been done in a somewhat peculiar manner.  The config
> option was called CONFIG_BLK_DEV_FD, and used to be at <Device
> Drivers>/<Block Devices>.  It is now not visible there.

It's visible here.

> However, Typing '/' BLK_DEV_FD in 'make menuconfig' returns its
> documentation, saying BLK_DEV_FD is dependent upon
> CONFIG_ARCH_MAY_HAVE_PC_FDC.  This latter variable isn't visible
> anywhere.

It's defined for you if the ARCHitecture (as the name implies)
supports floppies. It's set =y in all my kernels.

> I tried setting ARCH_MAY_HAVE_PC_FDC by hand in .config, but that didn't
> help.  'make menuconfig' just unset it again of its own accord.  Then I
> inserted BLK_DEV_FD into .config by hand and built the kernel.  I haven't
> tested it yet.
>
> All this seems rather strange.  Why shouldn't I be able to use my floppy
> drive?

Your kernel config/setup has something really weird.
ARCH_MAY_HAVE_PC_FDC is a boolean variable that it's set automatically
for you, since it's arch dependant. You cannot set it (nor unset it,
AFAIK).

May I recommend to completely uninstall your sources package and
delete /usr/src/linux (after a proper backup, of course), install them
again, and do a make oldconfig (after restoring your old .config)?

Because ARCH_MAY_HAVE_PC_FDC is something you should not to even think about.

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México

Re: [gentoo-user] Floppy disk support removed from kernel 3.4.9.

[Alan Mackenzie]

Hello, Canek.

On Sun, Oct 28, 2012 at 12:16:56PM -0600, Canek Peláez Valdés wrote:
> On Sun, Oct 28, 2012 at 11:48 AM, Alan Mackenzie <acm@muc.de> wrote:

> > Floppy disk support has been removed from kernel 3.4.9.  I'm not very
> > happy about this.  Does anybody know why, or by whom?

> Nobody removed anything; it's still there, in 3.6.3. I'm not using it,
> but I can select it without problems.

> > This removal has been done in a somewhat peculiar manner.  The config
> > option was called CONFIG_BLK_DEV_FD, and used to be at <Device
> > Drivers>/<Block Devices>.  It is now not visible there.

> It's visible here.

> > However, Typing '/' BLK_DEV_FD in 'make menuconfig' returns its
> > documentation, saying BLK_DEV_FD is dependent upon
> > CONFIG_ARCH_MAY_HAVE_PC_FDC.  This latter variable isn't visible
> > anywhere.

> It's defined for you if the ARCHitecture (as the name implies)
> supports floppies. It's set =y in all my kernels.

But, what does the "architecture" actually mean?

> > I tried setting ARCH_MAY_HAVE_PC_FDC by hand in .config, but that didn't
> > help.  'make menuconfig' just unset it again of its own accord.  Then I
> > inserted BLK_DEV_FD into .config by hand and built the kernel.  I haven't
> > tested it yet.

> > All this seems rather strange.  Why shouldn't I be able to use my floppy
> > drive?

> Your kernel config/setup has something really weird.

OK.  If I start the configuration afresh, I do indeed see the floppy disk
selector.  :-)

> ARCH_MAY_HAVE_PC_FDC is a boolean variable that it's set automatically
> for you, since it's arch dependant. You cannot set it (nor unset it,
> AFAIK).

Do you know where the source for 'make menuconfig' is in the source tree?

> May I recommend to completely uninstall your sources package and
> delete /usr/src/linux (after a proper backup, of course), install them
> again, and do a make oldconfig (after restoring your old .config)?

By starting again from scratch, it seems clear that the problem is in
some of the config options I have selected.

> Because ARCH_MAY_HAVE_PC_FDC is something you should not to even think about.

I agree with you there.  ;-)

Thanks for the help!

> Regards.
> -- 
> Canek Peláez Valdés

-- 
Alan Mackenzie (Nuremberg, Germany).

Re: [gentoo-user] Floppy disk support removed from kernel 3.4.9.

[Alan Mackenzie]

Hello, again!

On Sun, Oct 28, 2012 at 12:16:56PM -0600, Canek Peláez Valdés wrote:
> On Sun, Oct 28, 2012 at 11:48 AM, Alan Mackenzie <acm@muc.de> wrote:

> > All this seems rather strange.  Why shouldn't I be able to use my floppy
> > drive?

> Your kernel config/setup has something really weird.

Yes.  I'd mistakenly disabled CONFIG_ISA_DMA_API ("ISA-style DMA
support"), which BLK_DEV_FD was indirectly dependant on, via
ARCH_MAY_HAVE_PC_FDC.

This wasn't apparent in 'make menuconfig'; I had to grep through lots of
Kconfig files to track this down.

It's now fixed.  :-)

> ARCH_MAY_HAVE_PC_FDC is a boolean variable that it's set automatically
> for you, since it's arch dependant. You cannot set it (nor unset it,
> AFAIK).

Thanks again for the help.

> Regards.
> -- 
> Canek Peláez Valdés

-- 
Alan Mackenzie (Nuremberg, Germany).

Re: [gentoo-user] Floppy disk support removed from kernel 3.4.9.

[Canek Peláez Valdés]

On Sun, Oct 28, 2012 at 1:23 PM, Alan Mackenzie <acm@muc.de> wrote:
> Hello, Canek.
>
> On Sun, Oct 28, 2012 at 12:16:56PM -0600, Canek Peláez Valdés wrote:
>> On Sun, Oct 28, 2012 at 11:48 AM, Alan Mackenzie <acm@muc.de> wrote:
>
>> > Floppy disk support has been removed from kernel 3.4.9.  I'm not very
>> > happy about this.  Does anybody know why, or by whom?
>
>> Nobody removed anything; it's still there, in 3.6.3. I'm not using it,
>> but I can select it without problems.
>
>> > This removal has been done in a somewhat peculiar manner.  The config
>> > option was called CONFIG_BLK_DEV_FD, and used to be at <Device
>> > Drivers>/<Block Devices>.  It is now not visible there.
>
>> It's visible here.
>
>> > However, Typing '/' BLK_DEV_FD in 'make menuconfig' returns its
>> > documentation, saying BLK_DEV_FD is dependent upon
>> > CONFIG_ARCH_MAY_HAVE_PC_FDC.  This latter variable isn't visible
>> > anywhere.
>
>> It's defined for you if the ARCHitecture (as the name implies)
>> supports floppies. It's set =y in all my kernels.
>
> But, what does the "architecture" actually mean?

x86, ARM. As far as I know, in ARM you can only have floppies if you
connect an USB drive to it. So BLK_DEV_FD has no point in ARM. I
suppose the IBM s/390 mainframe computer doesn't use floppies either.

>> > I tried setting ARCH_MAY_HAVE_PC_FDC by hand in .config, but that didn't
>> > help.  'make menuconfig' just unset it again of its own accord.  Then I
>> > inserted BLK_DEV_FD into .config by hand and built the kernel.  I haven't
>> > tested it yet.
>
>> > All this seems rather strange.  Why shouldn't I be able to use my floppy
>> > drive?
>
>> Your kernel config/setup has something really weird.
>
> OK.  If I start the configuration afresh, I do indeed see the floppy disk
> selector.  :-)

You had a borked configuration, for some reason.

>> ARCH_MAY_HAVE_PC_FDC is a boolean variable that it's set automatically
>> for you, since it's arch dependant. You cannot set it (nor unset it,
>> AFAIK).
>
> Do you know where the source for 'make menuconfig' is in the source tree?

I believe is in scripts, along with kbuild. menuconfig is one of
several frontends to the build system.

>> May I recommend to completely uninstall your sources package and
>> delete /usr/src/linux (after a proper backup, of course), install them
>> again, and do a make oldconfig (after restoring your old .config)?
>
> By starting again from scratch, it seems clear that the problem is in
> some of the config options I have selected.

I thought that would help.

>> Because ARCH_MAY_HAVE_PC_FDC is something you should not to even think about.
>
> I agree with you there.  ;-)

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México