Re: [PATCH] drivers:staging: sources for ST core

[Greg KH <gregkh@suse.de>]

On Thu, Apr 01, 2010 at 12:57:06AM +0530, Pavan Savoy wrote:
> --- On Wed, 31/3/10, Greg KH <gregkh@suse.de> wrote:
> 
> > From: Greg KH <gregkh@suse.de>
> > Subject: Re: [PATCH] drivers:staging: sources for ST core
> > To: "Pavan Savoy" <pavan_savoy@ti.com>
> > Cc: "Marcel Holtmann" <marcel@holtmann.org>, alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org
> > Date: Wednesday, 31 March, 2010, 11:49 PM
> > On Wed, Mar 31, 2010 at 11:32:39PM
> > +0530, Pavan Savoy wrote:
> > > --- On Wed, 31/3/10, Greg KH <gregkh@suse.de>
> > wrote:
> > > 
> > > > From: Greg KH <gregkh@suse.de>
> > > > Subject: Re: [PATCH] drivers:staging: sources for
> > ST core
> > > > To: "Pavan Savoy" <pavan_savoy@ti.com>
> > > > Cc: "Marcel Holtmann" <marcel@holtmann.org>,
> > alan@lxorguk.ukuu.org.uk,
> > linux-kernel@vger.kernel.org
> > > > Date: Wednesday, 31 March, 2010, 11:00 PM
> > > > On Wed, Mar 31, 2010 at 04:20:22AM
> > > > +0530, Pavan Savoy wrote:
> > > > > 
> > > > > --- On Wed, 31/3/10, Pavan Savoy <pavan_savoy@ti.com>
> > > > wrote:
> > > > > 
> > > > > > From: Pavan Savoy <pavan_savoy@ti.com>
> > > > > > Subject: Re: [PATCH] drivers:staging:
> > sources for
> > > > ST core
> > > > > > To: gregkh@suse.de
> > > > > > Cc: "Marcel Holtmann" <marcel@holtmann.org>,
> > > > alan@lxorguk.ukuu.org.uk
> > > > > > Date: Wednesday, 31 March, 2010, 4:11
> > AM
> > > > > > --- On Wed, 31/3/10, Pavan Savoy
> > > > > > <pavan_savoy@yahoo.co.in>
> > > > > > wrote:
> > > > > > 
> > > > > > > From: Pavan Savoy <pavan_savoy@yahoo.co.in>
> > > > > > > Subject: Re: [PATCH]
> > drivers:staging:
> > > > sources for ST
> > > > > > core
> > > > > > > To: "pavan_savoy@yahoo.co.in"
> > > > > > <pavan_savoy@yahoo.co.in>
> > > > > > > Date: Wednesday, 31 March, 2010,
> > 4:06 AM
> > > > > > > > From: Greg KH [gregkh@suse.de]
> > > > > > > > Sent: Wednesday, March 31,
> > 2010 3:17
> > > > AM
> > > > > > > > To: Savoy, Pavan
> > > > > > > > Cc: Alan Cox; marcel@holtmann.org;
> > > > > > > > linux-kernel@vger.kernel.org
> > > > > > > > Subject: Re: [PATCH]
> > drivers:staging:
> > > > sources for
> > > > > > ST
> > > > > > > core
> > > > > > > > 
> > > > > > > > On Wed, Mar 31, 2010 at
> > 02:35:55AM
> > > > +0530, Pavan
> > > > > > Savoy
> > > > > > > > wrote:
> > > > > > > > > So, something like the
> > below is
> > > > ok, I have
> > > > > > > defined my
> > > > > > > > own pr_fmt,
> > > > > > > > > however default log
> > level on my
> > > > board is 7,
> > > > > > and
> > > > > > > hence
> > > > > > > > pr_info is a bit
> > > > > > > > > more annoying than
> > usual.
> > > > > > > > 
> > > > > > > > No, a driver should use
> > dev_dbg() and
> > > > other
> > > > > > > dev_printk()
> > > > > > > > calls, not
> > > > > > > > pr_debug() or anything like
> > that.
> > > > > > > > 
> > > > > > > > Please don't roll your own
> > formats, use
> > > > the ones
> > > > > > that
> > > > > > > are
> > > > > > > > well defined
> > > > > > > > and uniquely describe your
> > driver and
> > > > device in
> > > > > > a
> > > > > > > format
> > > > > > > > that the whole
> > > > > > > > kernel uses.
> > > > > > > 
> > > > > > 
> > > > > 
> > > > > forgot lkml the last time..
> > > > > 
> > > > > Nope, I couldn't find any instance of struct
> > device at
> > > > all,
> > > > > I need that to use dev_dbg right ? - None of
> > the
> > > > tty_*
> > > > > structure accessible by ldiscs seems to have
> > a
> > > > reference to
> > > > > it.
> > > > > Also I happened to look at other line
> > discipline
> > > > driver, if
> > > > > they have a smarter way of doing this, Nope
> > - n_tty,
> > > > n_hdlc,
> > > > > n_slip all seem to use plain old printks.
> > > > >? 
> > > > > Any clues ??
> > > > 
> > > > Sorry, you are correct, we only have a struct
> > kref right
> > > > now for tty
> > > > core objects, not a struct device.? So nevermind,
> > this
> > > > should be fine.
> > > 
> > > Oh cool. Thanks, So that leaves me with 1 pending item
> > from Alan which is to tie these 3 modules (KIM/Core/LL) up
> > onto a TTY device specific context, and avoid all global
> > ptrs.
> > > 
> > > So without that is it good to go in ?
> > 
> > Yes, care to do that and resubmit?
> 
> Oh, But that would take some major re-structuring with the driver, because with the existing driver being a platform_device/driver structure-I can't do that.
> 
> I have made it similar to TTY<->LDISCs, LDISCs register to TTY core, here BT/FM/GPS register to ST core.
> TTY has a array of ldisc registered which is global, locked resource, I have st_gdata which is global and locked resource.
> 
> Each ldisc is to be in context of tty, because multiple UART exist, but this is also a platform device and exports symbols for other drivers to register in, so essentially only 1 such device exist per platform.
> 
> I agree it's unlike other device drivers in kernel, But is this unacceptable this way ?

Think about what you just said, I think you answered your own question
:)

Please work on the change as requested.

thanks,

greg k-h