Re: [PATCH] [media] ddbridge: add IOCTLs

[Daniel Scheller <d.scheller.oss@gmail.com>]

Am Tue, 22 Aug 2017 17:21:16 +0200
schrieb Daniel Scheller <d.scheller.oss@gmail.com>:

> Am Tue, 22 Aug 2017 16:05:21 +0200
> schrieb Ralph Metzler <rjkm@metzlerbros.de>:
> 
> > Daniel Scheller writes:  
> >  > Am Sun, 20 Aug 2017 08:53:56 -0300
> >  > schrieb Mauro Carvalho Chehab <mchehab@s-opensource.com>:
> >  >     
> >  > > Em Sun, 20 Aug 2017 13:08:55 +0200
> >  > > Daniel Scheller <d.scheller.oss@gmail.com> escreveu:
> >  > >     
> >  > > > From: Daniel Scheller <d.scheller@gmx.net>
> >  > > > 
> >  > > > This patch adds back the IOCTL API/functionality which is
> >  > > > present in the upstream dddvb driver package. In comparison,
> >  > > > the IOCTL handler has been factored to a separate object (and
> >  > > > with that, some functionality from -core has been moved there
> >  > > > aswell), the IOCTLs are defined in an include in the uAPI,
> >  > > > and ioctl-number.txt is updated to document that there are
> >  > > > IOCTLs present in this driver.
> >  > > > 
> >  > > > Signed-off-by: Daniel Scheller <d.scheller@gmx.net>
> >  > > > ---
> >  > > > This patch depends on the ddbridge-0.9.29 bump, see [1]. The
> >  > > > functionality was part of the driver before.
> >  > > > 
> >  > > > [1] http://www.spinics.net/lists/linux-media/msg119911.html
> >  > > > 
> >  > > >  Documentation/ioctl/ioctl-number.txt        |   1 +
> >  > > >  MAINTAINERS                                 |   1 +
> >  > > >  drivers/media/pci/ddbridge/Makefile         |   2 +-
> >  > > >  drivers/media/pci/ddbridge/ddbridge-core.c  | 111 +--------
> >  > > >  drivers/media/pci/ddbridge/ddbridge-ioctl.c | 334
> >  > > > ++++++++++++++++++++++++++++
> >  > > > drivers/media/pci/ddbridge/ddbridge-ioctl.h |  32 +++
> >  > > > include/uapi/linux/ddbridge-ioctl.h         | 110 +++++++++ 7
> >  > > > files changed, 481 insertions(+), 110 deletions(-) create
> >  > > > mode 100644 drivers/media/pci/ddbridge/ddbridge-ioctl.c
> >  > > > create mode 100644
> >  > > > drivers/media/pci/ddbridge/ddbridge-ioctl.h create mode
> >  > > > 100644 include/uapi/linux/ddbridge-ioctl.h
> >  > > > 
> >  > > > diff --git a/Documentation/ioctl/ioctl-number.txt
> >  > > > b/Documentation/ioctl/ioctl-number.txt index
> >  > > > 3e3fdae5f3ed..d78d1cd092d2 100644 ---
> >  > > > a/Documentation/ioctl/ioctl-number.txt +++
> >  > > > b/Documentation/ioctl/ioctl-number.txt @@ -215,6 +215,7 @@
> >  > > > Code Seq#(hex)	Include File		Comments
> >  > > > 'c' A0-AF   arch/x86/include/asm/msr.h	conflict! 'd'
> >  > > > 00-FF	linux/char/drm/drm.h	conflict! 'd'
> >  > > > 02-40	pcmcia/ds.h		conflict! +'d'
> >  > > > 00-0B	linux/ddbridge-ioctl.h	conflict!      
> >  > > 
> >  > > That's where the problem with this patch starts: we don't add
> >  > > conflicts here :-)
> >  > > 
> >  > > We need more discussions with regards to the features added by
> >  > > this patchset.    
> >  > 
> >  > Understood. The "good" thing is that this isn't a requirement to
> >  > drive any tuner boards (at the moment), however we shouldn't lose
> >  > track on this. Since this is the only complaint for now:
> >  > 
> >  > - We need to clear with Ralph if changing the MAGIC to something
> >  >   different is an option. In the end, if we change the userspace
> >  > apps to include the uAPI header from mainline if available (else
> >  > fallback to what ie. dddvb carries), I don't see an issue with
> >  > this. But if userspace apps keep on using private stuff, this
> >  > will break ofc.
> >  > - Other option: Fork dddvb and change userspace apps accordingly,
> >  > and keep them in sync with upstream. Since we already have to
> >  > care about the kernel part, this option is rather suboptimal.
> >  > 
> >  > Ralph, Ping :-)    
> > 
> > Changing to something different from 'd' should be fine.
> > Is there anything still free?  
> 
> We could use 0xDD (for *D*igital *D*evices :-) ), subrange 0xc0-0xff
> or so, that isn't declared "in use" in ioctl-number.txt
> (0xDD/0x00-0x3f is used by some ZFCP driver). Other options would be
> ie. 0xD0-0xDA, 0xDC, 0xDE-0xE4. There are also other single values
> and value-ranges free, all according to ioctl-number.txt ofcourse.
> 
> Still yet not sure if this is everything that needs changing to be
> accepted though.

Ping.

Mauro, is there anything else you want to discuss or even want
changed besides the conflicting MAGIC? I'd like to get this stuff in so
we have everything from the original driver update patches in mainline
(and get this whole thing done, even).

Best regards,
Daniel Scheller
-- 
https://github.com/herrnst