linux-next: manual merge of the tty tree with the input tree

linux-next: manual merge of the tty tree with the input tree

[Stephen Rothwell]

[-- Attachment #1: Type: text/plain, Size: 1261 bytes --]

Hi Greg,

Today's linux-next merge of the tty tree got a conflict in
drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
goldfish - virtual input event driver") from the input tree and commit
4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
from the tty tree.

I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
not) and can carry the fix as necessary (no action is required).

-- 
Cheers,
Stephen Rothwell                    sfr@canb.auug.org.au

diff --cc drivers/input/keyboard/Kconfig
index 078305e,008f96a..0000000
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
  	  To compile this driver as a module, choose M here: the
  	  module will be called samsung-keypad.
  
+ if TTY
+ 
 +config KEYBOARD_GOLDFISH_EVENTS
 +	depends on GOLDFISH
 +	tristate "Generic Input Event device for Goldfish"
 +	help
 +	  Say Y here to get an input event device for the Goldfish virtual
 +	  device emulator.
 +
 +	  To compile this driver as a module, choose M here: the
 +	  module will be called goldfish-events.
 +
  config KEYBOARD_STOWAWAY
  	tristate "Stowaway keyboard"
  	select SERIO

[-- Attachment #2: Type: application/pgp-signature, Size: 836 bytes --]

Re: linux-next: manual merge of the tty tree with the input tree

[Greg KH]

On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> Hi Greg,
> 
> Today's linux-next merge of the tty tree got a conflict in
> drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> goldfish - virtual input event driver") from the input tree and commit
> 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> from the tty tree.
> 
> I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> not) and can carry the fix as necessary (no action is required).
> 
> -- 
> Cheers,
> Stephen Rothwell                    sfr@canb.auug.org.au
> 
> diff --cc drivers/input/keyboard/Kconfig
> index 078305e,008f96a..0000000
> --- a/drivers/input/keyboard/Kconfig
> +++ b/drivers/input/keyboard/Kconfig
> @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
>   	  To compile this driver as a module, choose M here: the
>   	  module will be called samsung-keypad.
>   
> + if TTY
> + 
>  +config KEYBOARD_GOLDFISH_EVENTS
>  +	depends on GOLDFISH
>  +	tristate "Generic Input Event device for Goldfish"
>  +	help
>  +	  Say Y here to get an input event device for the Goldfish virtual

Looks good, thanks.

greg k-h

Re: linux-next: manual merge of the tty tree with the input tree

[Dmitry Torokhov]

On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> > Hi Greg,
> > 
> > Today's linux-next merge of the tty tree got a conflict in
> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> > goldfish - virtual input event driver") from the input tree and commit
> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> > from the tty tree.
> > 
> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> > not) and can carry the fix as necessary (no action is required).
> > 
> > -- 
> > Cheers,
> > Stephen Rothwell                    sfr@canb.auug.org.au
> > 
> > diff --cc drivers/input/keyboard/Kconfig
> > index 078305e,008f96a..0000000
> > --- a/drivers/input/keyboard/Kconfig
> > +++ b/drivers/input/keyboard/Kconfig
> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
> >   	  To compile this driver as a module, choose M here: the
> >   	  module will be called samsung-keypad.
> >   
> > + if TTY
> > + 
> >  +config KEYBOARD_GOLDFISH_EVENTS
> >  +	depends on GOLDFISH
> >  +	tristate "Generic Input Event device for Goldfish"
> >  +	help
> >  +	  Say Y here to get an input event device for the Goldfish virtual
> 
> Looks good, thanks.

Greg,

Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
related to input. As far as I know nothing except serport driver
depends on tty and we do not need to introduce this kind of
dependencie. Anyone needing slim config can simply try disabling
input (or parts of it) without needing an artificial dependencies.

Thanks.

-- 
Dmitry

Re: linux-next: manual merge of the tty tree with the input tree

[Joe Millenbach]

On Mon, Jan 28, 2013 at 9:33 AM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
>> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
>> > Hi Greg,
>> >
>> > Today's linux-next merge of the tty tree got a conflict in
>> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
>> > goldfish - virtual input event driver") from the input tree and commit
>> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
>> > from the tty tree.
>> >
>> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
>> > not) and can carry the fix as necessary (no action is required).
>> >
>> > --
>> > Cheers,
>> > Stephen Rothwell                    sfr@canb.auug.org.au
>> >
>> > diff --cc drivers/input/keyboard/Kconfig
>> > index 078305e,008f96a..0000000
>> > --- a/drivers/input/keyboard/Kconfig
>> > +++ b/drivers/input/keyboard/Kconfig
>> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
>> >       To compile this driver as a module, choose M here: the
>> >       module will be called samsung-keypad.
>> >
>> > + if TTY
>> > +
>> >  +config KEYBOARD_GOLDFISH_EVENTS
>> >  +  depends on GOLDFISH
>> >  +  tristate "Generic Input Event device for Goldfish"
>> >  +  help
>> >  +    Say Y here to get an input event device for the Goldfish virtual
>>
>> Looks good, thanks.
>
> Greg,
>
> Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
> related to input. As far as I know nothing except serport driver
> depends on tty and we do not need to introduce this kind of
> dependencie. Anyone needing slim config can simply try disabling
> input (or parts of it) without needing an artificial dependencies.
>
> Thanks.
>
> --
> Dmitry

Dmitry and Greg,

SERIO needs TTY, and the majority of the input changes are adding "depends on
TTY" to things that "select SERIO" as they break the dependency chain.  In other
words, enabling a component that selects SERIO will turn SERIO on even when
SERIO depends on TTY and TTY is disabled.

Joe

Re: linux-next: manual merge of the tty tree with the input tree

[Dmitry Torokhov]

On Mon, Jan 28, 2013 at 02:09:31PM -0800, Joe Millenbach wrote:
> On Mon, Jan 28, 2013 at 9:33 AM, Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> > On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
> >> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> >> > Hi Greg,
> >> >
> >> > Today's linux-next merge of the tty tree got a conflict in
> >> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> >> > goldfish - virtual input event driver") from the input tree and commit
> >> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> >> > from the tty tree.
> >> >
> >> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> >> > not) and can carry the fix as necessary (no action is required).
> >> >
> >> > --
> >> > Cheers,
> >> > Stephen Rothwell                    sfr@canb.auug.org.au
> >> >
> >> > diff --cc drivers/input/keyboard/Kconfig
> >> > index 078305e,008f96a..0000000
> >> > --- a/drivers/input/keyboard/Kconfig
> >> > +++ b/drivers/input/keyboard/Kconfig
> >> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
> >> >       To compile this driver as a module, choose M here: the
> >> >       module will be called samsung-keypad.
> >> >
> >> > + if TTY
> >> > +
> >> >  +config KEYBOARD_GOLDFISH_EVENTS
> >> >  +  depends on GOLDFISH
> >> >  +  tristate "Generic Input Event device for Goldfish"
> >> >  +  help
> >> >  +    Say Y here to get an input event device for the Goldfish virtual
> >>
> >> Looks good, thanks.
> >
> > Greg,
> >
> > Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
> > related to input. As far as I know nothing except serport driver
> > depends on tty and we do not need to introduce this kind of
> > dependencie. Anyone needing slim config can simply try disabling
> > input (or parts of it) without needing an artificial dependencies.
> >
> > Thanks.
> >
> > --
> > Dmitry
> 
> Dmitry and Greg,
> 
> SERIO needs TTY, 

No it does not. There is only one (1) serio driver that needs the tty
layer and that is serport.

> and the majority of the input changes are adding "depends on TTY" to
> things that "select SERIO" as they break the dependency chain.  In
> other words, enabling a component that selects SERIO will turn SERIO
> on even when SERIO depends on TTY and TTY is disabled.

Except that it does not. Are you confusing SERIO with SERIAL by any
chance?

In the future it would be nice if you CCed people involved in the
subsystem you are changing.

Thanks.

-- 
Dmitry

Re: linux-next: manual merge of the tty tree with the input tree

[Josh Triplett]

On Mon, Jan 28, 2013 at 02:44:43PM -0800, Dmitry Torokhov wrote:
> On Mon, Jan 28, 2013 at 02:09:31PM -0800, Joe Millenbach wrote:
> > On Mon, Jan 28, 2013 at 9:33 AM, Dmitry Torokhov
> > <dmitry.torokhov@gmail.com> wrote:
> > > On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
> > >> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> > >> > Hi Greg,
> > >> >
> > >> > Today's linux-next merge of the tty tree got a conflict in
> > >> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> > >> > goldfish - virtual input event driver") from the input tree and commit
> > >> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> > >> > from the tty tree.
> > >> >
> > >> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> > >> > not) and can carry the fix as necessary (no action is required).
> > >> >
> > >> > --
> > >> > Cheers,
> > >> > Stephen Rothwell                    sfr@canb.auug.org.au
> > >> >
> > >> > diff --cc drivers/input/keyboard/Kconfig
> > >> > index 078305e,008f96a..0000000
> > >> > --- a/drivers/input/keyboard/Kconfig
> > >> > +++ b/drivers/input/keyboard/Kconfig
> > >> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
> > >> >       To compile this driver as a module, choose M here: the
> > >> >       module will be called samsung-keypad.
> > >> >
> > >> > + if TTY
> > >> > +
> > >> >  +config KEYBOARD_GOLDFISH_EVENTS
> > >> >  +  depends on GOLDFISH
> > >> >  +  tristate "Generic Input Event device for Goldfish"
> > >> >  +  help
> > >> >  +    Say Y here to get an input event device for the Goldfish virtual
> > >>
> > >> Looks good, thanks.
> > >
> > > Greg,
> > >
> > > Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
> > > related to input. As far as I know nothing except serport driver
> > > depends on tty and we do not need to introduce this kind of
> > > dependencie. Anyone needing slim config can simply try disabling
> > > input (or parts of it) without needing an artificial dependencies.
> > >
> > > Thanks.
> > >
> > > --
> > > Dmitry
> > 
> > Dmitry and Greg,
> > 
> > SERIO needs TTY, 
> 
> No it does not. There is only one (1) serio driver that needs the tty
> layer and that is serport.
> 
> > and the majority of the input changes are adding "depends on TTY" to
> > things that "select SERIO" as they break the dependency chain.  In
> > other words, enabling a component that selects SERIO will turn SERIO
> > on even when SERIO depends on TTY and TTY is disabled.
> 
> Except that it does not. Are you confusing SERIO with SERIAL by any
> chance?

A few serial drivers don't actually need the TTY layer.  However, most
do, including many that don't obviously appear to at first glance.  For
instance, MOUSE_PS2 doesn't *appear* to need TTY, but without the
dependency, having MOUSE_PS2 enabled and TTY disabled produces a kernel
that doesn't build.  (Also keep in mind that many other headers include
<linux/tty.h>.)  Many of the drivers that don't actually need TTY
nonetheless won't typically appear on systems small enough to want to
compile out TTY.

In any case, it seems simple enough to whittle down dependencies on TTY
later on, but for a first pass, the conserative approach seems
preferable.

> In the future it would be nice if you CCed people involved in the
> subsystem you are changing.

Such as the maintainers of the TTY and serial layers?  Alan Cox OKed
this conservative addition of dependencies in the original version of
this change, and Greg had no complaints at the time.

- Josh Triplett

Re: linux-next: manual merge of the tty tree with the input tree

[Dmitry Torokhov]

On Tue, Jan 29, 2013 at 10:59:17AM +1100, Josh Triplett wrote:
> On Mon, Jan 28, 2013 at 02:44:43PM -0800, Dmitry Torokhov wrote:
> > On Mon, Jan 28, 2013 at 02:09:31PM -0800, Joe Millenbach wrote:
> > > On Mon, Jan 28, 2013 at 9:33 AM, Dmitry Torokhov
> > > <dmitry.torokhov@gmail.com> wrote:
> > > > On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
> > > >> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> > > >> > Hi Greg,
> > > >> >
> > > >> > Today's linux-next merge of the tty tree got a conflict in
> > > >> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> > > >> > goldfish - virtual input event driver") from the input tree and commit
> > > >> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> > > >> > from the tty tree.
> > > >> >
> > > >> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> > > >> > not) and can carry the fix as necessary (no action is required).
> > > >> >
> > > >> > --
> > > >> > Cheers,
> > > >> > Stephen Rothwell                    sfr@canb.auug.org.au
> > > >> >
> > > >> > diff --cc drivers/input/keyboard/Kconfig
> > > >> > index 078305e,008f96a..0000000
> > > >> > --- a/drivers/input/keyboard/Kconfig
> > > >> > +++ b/drivers/input/keyboard/Kconfig
> > > >> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
> > > >> >       To compile this driver as a module, choose M here: the
> > > >> >       module will be called samsung-keypad.
> > > >> >
> > > >> > + if TTY
> > > >> > +
> > > >> >  +config KEYBOARD_GOLDFISH_EVENTS
> > > >> >  +  depends on GOLDFISH
> > > >> >  +  tristate "Generic Input Event device for Goldfish"
> > > >> >  +  help
> > > >> >  +    Say Y here to get an input event device for the Goldfish virtual
> > > >>
> > > >> Looks good, thanks.
> > > >
> > > > Greg,
> > > >
> > > > Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
> > > > related to input. As far as I know nothing except serport driver
> > > > depends on tty and we do not need to introduce this kind of
> > > > dependencie. Anyone needing slim config can simply try disabling
> > > > input (or parts of it) without needing an artificial dependencies.
> > > >
> > > > Thanks.
> > > >
> > > > --
> > > > Dmitry
> > > 
> > > Dmitry and Greg,
> > > 
> > > SERIO needs TTY, 
> > 
> > No it does not. There is only one (1) serio driver that needs the tty
> > layer and that is serport.
> > 
> > > and the majority of the input changes are adding "depends on TTY" to
> > > things that "select SERIO" as they break the dependency chain.  In
> > > other words, enabling a component that selects SERIO will turn SERIO
> > > on even when SERIO depends on TTY and TTY is disabled.
> > 
> > Except that it does not. Are you confusing SERIO with SERIAL by any
> > chance?
> 
> A few serial drivers don't actually need the TTY layer.  However, most

Can you please tell me why you are talking about serial layer here?

> do, including many that don't obviously appear to at first glance.  For
> instance, MOUSE_PS2 doesn't *appear* to need TTY, but without the
> dependency, having MOUSE_PS2 enabled and TTY disabled produces a kernel
> that doesn't build.

Compile log please.

>  (Also keep in mind that many other headers include
> <linux/tty.h>.)  Many of the drivers that don't actually need TTY
> nonetheless won't typically appear on systems small enough to want to
> compile out TTY.
> 
> In any case, it seems simple enough to whittle down dependencies on TTY
> later on, but for a first pass, the conserative approach seems
> preferable.

However my approach would be not to touch anything except serport
driver (which indeed depends on TTY layer).

> 
> > In the future it would be nice if you CCed people involved in the
> > subsystem you are changing.
> 
> Such as the maintainers of the TTY and serial layers?  Alan Cox OKed
> this conservative addition of dependencies in the original version of
> this change, and Greg had no complaints at the time.

Maintainer of _SERIO_ (not SERIAL, SERIO) layer, yours truly.

-- 
Dmitry

Re: linux-next: manual merge of the tty tree with the input tree

[Josh Triplett]

On Mon, Jan 28, 2013 at 04:23:57PM -0800, Dmitry Torokhov wrote:
> On Tue, Jan 29, 2013 at 10:59:17AM +1100, Josh Triplett wrote:
> > On Mon, Jan 28, 2013 at 02:44:43PM -0800, Dmitry Torokhov wrote:
> > > On Mon, Jan 28, 2013 at 02:09:31PM -0800, Joe Millenbach wrote:
> > > > On Mon, Jan 28, 2013 at 9:33 AM, Dmitry Torokhov
> > > > <dmitry.torokhov@gmail.com> wrote:
> > > > > On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
> > > > >> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> > > > >> > Hi Greg,
> > > > >> >
> > > > >> > Today's linux-next merge of the tty tree got a conflict in
> > > > >> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> > > > >> > goldfish - virtual input event driver") from the input tree and commit
> > > > >> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> > > > >> > from the tty tree.
> > > > >> >
> > > > >> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> > > > >> > not) and can carry the fix as necessary (no action is required).
> > > > >> >
> > > > >> > --
> > > > >> > Cheers,
> > > > >> > Stephen Rothwell                    sfr@canb.auug.org.au
> > > > >> >
> > > > >> > diff --cc drivers/input/keyboard/Kconfig
> > > > >> > index 078305e,008f96a..0000000
> > > > >> > --- a/drivers/input/keyboard/Kconfig
> > > > >> > +++ b/drivers/input/keyboard/Kconfig
> > > > >> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
> > > > >> >       To compile this driver as a module, choose M here: the
> > > > >> >       module will be called samsung-keypad.
> > > > >> >
> > > > >> > + if TTY
> > > > >> > +
> > > > >> >  +config KEYBOARD_GOLDFISH_EVENTS
> > > > >> >  +  depends on GOLDFISH
> > > > >> >  +  tristate "Generic Input Event device for Goldfish"
> > > > >> >  +  help
> > > > >> >  +    Say Y here to get an input event device for the Goldfish virtual
> > > > >>
> > > > >> Looks good, thanks.
> > > > >
> > > > > Greg,
> > > > >
> > > > > Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
> > > > > related to input. As far as I know nothing except serport driver
> > > > > depends on tty and we do not need to introduce this kind of
> > > > > dependencie. Anyone needing slim config can simply try disabling
> > > > > input (or parts of it) without needing an artificial dependencies.
> > > > >
> > > > > Thanks.
> > > > >
> > > > > --
> > > > > Dmitry
> > > > 
> > > > Dmitry and Greg,
> > > > 
> > > > SERIO needs TTY, 
> > > 
> > > No it does not. There is only one (1) serio driver that needs the tty
> > > layer and that is serport.
> > > 
> > > > and the majority of the input changes are adding "depends on TTY" to
> > > > things that "select SERIO" as they break the dependency chain.  In
> > > > other words, enabling a component that selects SERIO will turn SERIO
> > > > on even when SERIO depends on TTY and TTY is disabled.
> > > 
> > > Except that it does not. Are you confusing SERIO with SERIAL by any
> > > chance?
> > 
> > A few serial drivers don't actually need the TTY layer.  However, most
> 
> Can you please tell me why you are talking about serial layer here?

Probably terminology sloppiness.  Insert noun for "things that depend on
SERIO" here.

> > do, including many that don't obviously appear to at first glance.  For
> > instance, MOUSE_PS2 doesn't *appear* to need TTY, but without the
> > dependency, having MOUSE_PS2 enabled and TTY disabled produces a kernel
> > that doesn't build.
> 
> Compile log please.

http://marc.info/?l=linux-kernel&m=134555498507747&w=1

IIRC, produced by dropping the "depends on TTY" from MOUSE_PS2, enabling
MOUSE_PS2, leaving TTY disabled, and changing nothing else.  (In
particular, not changing anything related to serport directly.)

> >  (Also keep in mind that many other headers include
> > <linux/tty.h>.)  Many of the drivers that don't actually need TTY
> > nonetheless won't typically appear on systems small enough to want to
> > compile out TTY.
> > 
> > In any case, it seems simple enough to whittle down dependencies on TTY
> > later on, but for a first pass, the conserative approach seems
> > preferable.
> 
> However my approach would be not to touch anything except serport
> driver (which indeed depends on TTY layer).

Quite a bit more than that depends on the TTY layer.

> > > In the future it would be nice if you CCed people involved in the
> > > subsystem you are changing.
> > 
> > Such as the maintainers of the TTY and serial layers?  Alan Cox OKed
> > this conservative addition of dependencies in the original version of
> > this change, and Greg had no complaints at the time.
> 
> Maintainer of _SERIO_ (not SERIAL, SERIO) layer, yours truly.

This change affected the dependencies of several hundred drivers, and
the output of get_maintainer.pl included hundreds of email addresses.
Spamming *all* of them for a one-line change to the dependencies of a
Kconfig option, when that change acts as a no-op except on systems
trying to use CONFIG_TTY=n, seemed imprudent.  Given that this was a
change to the TTY layer, and not to the SERIO subsystem other than its
dependencies (along with the dependencies of hundreds of other drivers),
SERIO didn't particularly seem to stand out here as one to keep the CC
for.  In any case, sorry you didn't hear about this sooner.

Given that the kernel without this patch effectively has CONFIG_TTY=y
hardcoded, and that CONFIG_TTY=y remains the common case, it seems
fairly reasonable to bias in favor of making sure that all
Kconfig-supported configurations will actually build rather than trying
to maximize the number of drivers buildable with CONFIG_TTY=n.  It seems
easy enough to drop dependencies on TTY later, but at the moment all the
dependencies on TTY came from either observed build failures without it
or fairly clear dependencies on TTY (such as the use of tty_* functions,
inclusion of linux/tty.h, or selection of a driver that does one of
those).

- Josh Triplett

Re: linux-next: manual merge of the tty tree with the input tree

[Dmitry Torokhov]

On Tue, Jan 29, 2013 at 04:13:21PM +1100, Josh Triplett wrote:
> On Mon, Jan 28, 2013 at 04:23:57PM -0800, Dmitry Torokhov wrote:
> > On Tue, Jan 29, 2013 at 10:59:17AM +1100, Josh Triplett wrote:
> > > On Mon, Jan 28, 2013 at 02:44:43PM -0800, Dmitry Torokhov wrote:
> > > > On Mon, Jan 28, 2013 at 02:09:31PM -0800, Joe Millenbach wrote:
> > > > > On Mon, Jan 28, 2013 at 9:33 AM, Dmitry Torokhov
> > > > > <dmitry.torokhov@gmail.com> wrote:
> > > > > > On Mon, Jan 28, 2013 at 06:46:15AM -0800, Greg KH wrote:
> > > > > >> On Mon, Jan 28, 2013 at 08:44:24PM +1100, Stephen Rothwell wrote:
> > > > > >> > Hi Greg,
> > > > > >> >
> > > > > >> > Today's linux-next merge of the tty tree got a conflict in
> > > > > >> > drivers/input/keyboard/Kconfig between commit 6f2ac009f29b ("Input:
> > > > > >> > goldfish - virtual input event driver") from the input tree and commit
> > > > > >> > 4f73bc4dd3e8 ("tty: Added a CONFIG_TTY option to allow removal of TTY")
> > > > > >> > from the tty tree.
> > > > > >> >
> > > > > >> > I fixed it up (see below - I am not sure if GOLDFISH_EVENTS needs TTY or
> > > > > >> > not) and can carry the fix as necessary (no action is required).
> > > > > >> >
> > > > > >> > --
> > > > > >> > Cheers,
> > > > > >> > Stephen Rothwell                    sfr@canb.auug.org.au
> > > > > >> >
> > > > > >> > diff --cc drivers/input/keyboard/Kconfig
> > > > > >> > index 078305e,008f96a..0000000
> > > > > >> > --- a/drivers/input/keyboard/Kconfig
> > > > > >> > +++ b/drivers/input/keyboard/Kconfig
> > > > > >> > @@@ -479,16 -482,8 +482,18 @@@ config KEYBOARD_SAMSUN
> > > > > >> >       To compile this driver as a module, choose M here: the
> > > > > >> >       module will be called samsung-keypad.
> > > > > >> >
> > > > > >> > + if TTY
> > > > > >> > +
> > > > > >> >  +config KEYBOARD_GOLDFISH_EVENTS
> > > > > >> >  +  depends on GOLDFISH
> > > > > >> >  +  tristate "Generic Input Event device for Goldfish"
> > > > > >> >  +  help
> > > > > >> >  +    Say Y here to get an input event device for the Goldfish virtual
> > > > > >>
> > > > > >> Looks good, thanks.
> > > > > >
> > > > > > Greg,
> > > > > >
> > > > > > Please drop 4f73bc4dd3e8563ef4109f293a092820dff66d92, at least the parts
> > > > > > related to input. As far as I know nothing except serport driver
> > > > > > depends on tty and we do not need to introduce this kind of
> > > > > > dependencie. Anyone needing slim config can simply try disabling
> > > > > > input (or parts of it) without needing an artificial dependencies.
> > > > > >
> > > > > > Thanks.
> > > > > >
> > > > > > --
> > > > > > Dmitry
> > > > > 
> > > > > Dmitry and Greg,
> > > > > 
> > > > > SERIO needs TTY, 
> > > > 
> > > > No it does not. There is only one (1) serio driver that needs the tty
> > > > layer and that is serport.
> > > > 
> > > > > and the majority of the input changes are adding "depends on TTY" to
> > > > > things that "select SERIO" as they break the dependency chain.  In
> > > > > other words, enabling a component that selects SERIO will turn SERIO
> > > > > on even when SERIO depends on TTY and TTY is disabled.
> > > > 
> > > > Except that it does not. Are you confusing SERIO with SERIAL by any
> > > > chance?
> > > 
> > > A few serial drivers don't actually need the TTY layer.  However, most
> > 
> > Can you please tell me why you are talking about serial layer here?
> 
> Probably terminology sloppiness.  Insert noun for "things that depend on
> SERIO" here. 

Still does not make sense as SERIO subsystem does not depend on TTY, a
single driver belonging to it does.

 
> > > do, including many that don't obviously appear to at first glance.  For
> > > instance, MOUSE_PS2 doesn't *appear* to need TTY, but without the
> > > dependency, having MOUSE_PS2 enabled and TTY disabled produces a kernel
> > > that doesn't build.
> > 
> > Compile log please.
> 
> http://marc.info/?l=linux-kernel&m=134555498507747&w=1
> 
> IIRC, produced by dropping the "depends on TTY" from MOUSE_PS2, enabling
> MOUSE_PS2, leaving TTY disabled, and changing nothing else.  (In
> particular, not changing anything related to serport directly.)

Right, because serport (one single diriver outr of all of them) does
depend on TTY.

> 
> > >  (Also keep in mind that many other headers include
> > > <linux/tty.h>.)  Many of the drivers that don't actually need TTY
> > > nonetheless won't typically appear on systems small enough to want to
> > > compile out TTY.
> > > 
> > > In any case, it seems simple enough to whittle down dependencies on TTY
> > > later on, but for a first pass, the conserative approach seems
> > > preferable.
> > 
> > However my approach would be not to touch anything except serport
> > driver (which indeed depends on TTY layer).
> 
> Quite a bit more than that depends on the TTY layer.

No, if you look at the log you mention above the only build failure is
coming from serport driver, exactly as I said. There is exactly *ONE*
driver in drivers/input/serio that depends on tty layer.

> 
> > > > In the future it would be nice if you CCed people involved in the
> > > > subsystem you are changing.
> > > 
> > > Such as the maintainers of the TTY and serial layers?  Alan Cox OKed
> > > this conservative addition of dependencies in the original version of
> > > this change, and Greg had no complaints at the time.
> > 
> > Maintainer of _SERIO_ (not SERIAL, SERIO) layer, yours truly.
> 
> This change affected the dependencies of several hundred drivers, and
> the output of get_maintainer.pl included hundreds of email addresses.
> Spamming *all* of them for a one-line change to the dependencies of a
> Kconfig option, when that change acts as a no-op except on systems
> trying to use CONFIG_TTY=n, seemed imprudent.  Given that this was a
> change to the TTY layer, and not to the SERIO subsystem other than its
> dependencies (along with the dependencies of hundreds of other drivers),
> SERIO didn't particularly seem to stand out here as one to keep the CC
> for.

And yet, if you bothered to CC me on it I'd tell you right away that
there is no point whatsoever to make this misguided change. In general,
if you think you need to add a new dependency to majority of the
drivers in the subsystem maybe you should ask yourself if what you are
doing is right thing or not.

Once again SERIO != SERIAL and has no direct relation to the TTY.

Please revert the input changes and add *ONE* new dependency to the
serport driver.

Thanks.

-- 
Dmitry

Re: linux-next: manual merge of the tty tree with the input tree

[Joe Millenbach]

On Mon, Jan 28, 2013 at 9:33 PM, Dmitry Torokhov
<dmitry.torokhov@gmail.com> wrote:
> Please revert the input changes and add *ONE* new dependency to the
> serport driver.
>
> Thanks.
>
> --
> Dmitry

Apologies on this.  I must have misunderstood the problem originally,
and I definitely misunderstood your solution until I looked at it
again.  I just went through applying the changes I'd created minus the
driver/input changes, plus your SERPORT TTY dependency.  You were
right that it solves the dependency issue and is much more elegant.  I
thought it was going to leave dangling select dependencies for users
to deal with later.  Sorry I was so hesitant at first.

I'll be making up a new patch for Greg after I get it reviewed.  And
thank you for your help and persistence in this, Dmitry.

- Joe

Re: linux-next: manual merge of the tty tree with the input tree

[Dmitry Torokhov]

Hi Joe,

On Mon, Jan 28, 2013 at 10:26:47PM -0800, Joe Millenbach wrote:
> On Mon, Jan 28, 2013 at 9:33 PM, Dmitry Torokhov
> <dmitry.torokhov@gmail.com> wrote:
> > Please revert the input changes and add *ONE* new dependency to the
> > serport driver.
> >
> > Thanks.
> >
> > --
> > Dmitry
> 
> Apologies on this.  I must have misunderstood the problem originally,
> and I definitely misunderstood your solution until I looked at it
> again.  I just went through applying the changes I'd created minus the
> driver/input changes, plus your SERPORT TTY dependency.  You were
> right that it solves the dependency issue and is much more elegant.  I
> thought it was going to leave dangling select dependencies for users
> to deal with later.  Sorry I was so hesitant at first.
> 
> I'll be making up a new patch for Greg after I get it reviewed.

Thank you for making the changes.

By the "dangling select dependencies" I assume you mean "select SERIO"
that several drivers do? "select SERIO" selects only serio core which is
self contained and has no additional dependencies [so far], that is why
it is being selected rather than being depended upon.

Thanks.

-- 
Dmitry