Re: [PATCH for 4.5] media.h: use hex values for the range offsets, move connectors base up.

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

On Thursday 03 March 2016 11:03:02 Hans Verkuil wrote:
> On 03/03/16 10:52, Laurent Pinchart wrote:
> > On Monday 29 February 2016 09:02:47 Hans Verkuil wrote:
> >> Make the base offset hexadecimal to simplify debugging since the base
> >> addresses are hex too.
> >> 
> >> The offsets for connectors is also changed to start after the 'reserved'
> >> range 0x10000-0x2ffff.
> >> 
> >> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> >> 
> >> diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h
> >> index 95e126e..79960ae 100644
> >> --- a/include/uapi/linux/media.h
> >> +++ b/include/uapi/linux/media.h
> >> @@ -66,17 +66,17 @@ struct media_device_info {
> >> 
> >>  /*
> >>  
> >>   * DVB entities
> >>   */
> >> 
> >> -#define MEDIA_ENT_F_DTV_DEMOD		(MEDIA_ENT_F_BASE + 1)
> >> -#define MEDIA_ENT_F_TS_DEMUX		(MEDIA_ENT_F_BASE + 2)
> >> -#define MEDIA_ENT_F_DTV_CA		(MEDIA_ENT_F_BASE + 3)
> >> -#define MEDIA_ENT_F_DTV_NET_DECAP	(MEDIA_ENT_F_BASE + 4)
> >> +#define MEDIA_ENT_F_DTV_DEMOD		(MEDIA_ENT_F_BASE + 0x00001)
> >> +#define MEDIA_ENT_F_TS_DEMUX		(MEDIA_ENT_F_BASE + 0x00002)
> >> +#define MEDIA_ENT_F_DTV_CA		(MEDIA_ENT_F_BASE + 0x00003)
> >> +#define MEDIA_ENT_F_DTV_NET_DECAP	(MEDIA_ENT_F_BASE + 0x00004)
> >> 
> >>  /*
> >>  
> >>   * I/O entities
> >>   */
> >> 
> >> -#define MEDIA_ENT_F_IO_DTV		(MEDIA_ENT_F_BASE + 1001)
> >> -#define MEDIA_ENT_F_IO_VBI		(MEDIA_ENT_F_BASE + 1002)
> >> -#define MEDIA_ENT_F_IO_SWRADIO		(MEDIA_ENT_F_BASE + 1003)
> >> +#define MEDIA_ENT_F_IO_DTV		(MEDIA_ENT_F_BASE + 0x01001)
> >> +#define MEDIA_ENT_F_IO_VBI		(MEDIA_ENT_F_BASE + 0x01002)
> >> +#define MEDIA_ENT_F_IO_SWRADIO		(MEDIA_ENT_F_BASE + 0x01003)
> >> 
> >>  /*
> >>  
> >>   * Analog TV IF-PLL decoders
> >> 
> >> @@ -84,23 +84,23 @@ struct media_device_info {
> >> 
> >>   * It is a responsibility of the master/bridge drivers to create links
> >>   * for MEDIA_ENT_F_IF_VID_DECODER and MEDIA_ENT_F_IF_AUD_DECODER.
> >>   */
> >> 
> >> -#define MEDIA_ENT_F_IF_VID_DECODER	(MEDIA_ENT_F_BASE + 2001)
> >> -#define MEDIA_ENT_F_IF_AUD_DECODER	(MEDIA_ENT_F_BASE + 2002)
> >> +#define MEDIA_ENT_F_IF_VID_DECODER	(MEDIA_ENT_F_BASE + 0x02001)
> >> +#define MEDIA_ENT_F_IF_AUD_DECODER	(MEDIA_ENT_F_BASE + 0x02002)
> >> 
> >>  /*
> >>  
> >>   * Audio Entity Functions
> >>   */
> >> 
> >> -#define MEDIA_ENT_F_AUDIO_CAPTURE	(MEDIA_ENT_F_BASE + 3000)
> >> -#define MEDIA_ENT_F_AUDIO_PLAYBACK	(MEDIA_ENT_F_BASE + 3001)
> >> -#define MEDIA_ENT_F_AUDIO_MIXER		(MEDIA_ENT_F_BASE + 3002)
> >> +#define MEDIA_ENT_F_AUDIO_CAPTURE	(MEDIA_ENT_F_BASE + 0x03000)
> > 
> > Why does this one start at 0x*000 while the others start at 0x*0001 ? I
> > know that the problem predates your patch.
> 
> I hadn't noticed. It is my personal preference not to start with 0.
> But it is not needed in this case, at least not today.
> 
> I think starting with 1 will help if we ever want to do AND operations
> on the ID. Then it is nice that the lower 16 bits can't be 0 for valid
> IDs.

I'm fine starting at 1, would you like to resubmit this patch to change that ?

> >> +#define MEDIA_ENT_F_AUDIO_PLAYBACK	(MEDIA_ENT_F_BASE + 0x03001)
> >> +#define MEDIA_ENT_F_AUDIO_MIXER		(MEDIA_ENT_F_BASE + 0x03002)
> >> 
> >>  /*
> >>  
> >>   * Connectors
> >>   */
> >>  
> >>  /* It is a responsibility of the entity drivers to add connectors and
> >>  links
> >> 
> >> */ -#define MEDIA_ENT_F_CONN_RF		(MEDIA_ENT_F_BASE + 10001)
> >> -#define MEDIA_ENT_F_CONN_SVIDEO		(MEDIA_ENT_F_BASE + 10002)
> >> -#define MEDIA_ENT_F_CONN_COMPOSITE	(MEDIA_ENT_F_BASE + 10003)
> >> +#define MEDIA_ENT_F_CONN_RF		(MEDIA_ENT_F_BASE + 0x30001)
> > 
> > Anything wrong with 0x4xxx ?
> 
> Possibly overkill, but Sakari preferred to make more generous use of the
> 32 bit space. And since there may potentially be a lot of connector types
> I thought I gave it plenty of space. Of course, if we ever need that many,
> then something is seriously wrong...

And you'd need space *after* the existing connector IDs, not before. Using 
0x30000 instead of 0x4000 has the effect of reserving plenty of space for 
audio functions, not for connectors. I think 0x4000 should be fine.

> >> +#define MEDIA_ENT_F_CONN_SVIDEO		(MEDIA_ENT_F_BASE + 0x30002)
> >> +#define MEDIA_ENT_F_CONN_COMPOSITE	(MEDIA_ENT_F_BASE + 0x30003)
> >> 
> >>  /*
> >>   * Don't touch on those. The ranges MEDIA_ENT_F_OLD_BASE and

-- 
Regards,

Laurent Pinchart