Hi Hans,
On Saturday 28 August 2010 13:02:22 Hans Verkuil wrote:
> On Friday, August 20, 2010 17:29:09 Laurent Pinchart wrote:
[snip]
> > diff --git a/Documentation/media-framework.txt
> > b/Documentation/media-framework.txt index 66f7f6c..74a137d 100644
> > --- a/Documentation/media-framework.txt
> > +++ b/Documentation/media-framework.txt
[snip]
> > +The media_entity_desc structure is defined as
> > +
> > +- struct media_entity_desc
> > +
> > +__u32 id Entity id, set by the application. When the id
> > is
> > + or'ed with MEDIA_ENTITY_ID_FLAG_NEXT, the driver
> > + clears the flag and returns the first entity with a
> > + larger id.
> > +char name[32] Entity name. UTF-8 NULL-terminated string.
>
> Why UTF-8 instead of ASCII?
Because vendor-specific names could include non-ASCII characters (same reason
for the model name in the media_device structure, if we decice to make the
model name ASCII I'll make the entity name ASCII as well).
[snip]
> > +struct media_entity_desc {
> > + __u32 id;
> > + char name[32];
> > + __u32 type;
> > + __u32 revision;
> > + __u32 flags;
> > + __u32 group_id;
> > + __u16 pads;
> > + __u16 links;
> > +
> > + __u32 reserved[4];
> > +
> > + union {
> > + /* Node specifications */
> > + struct {
> > + __u32 major;
> > + __u32 minor;
> > + } v4l;
> > + struct {
> > + __u32 major;
> > + __u32 minor;
> > + } fb;
> > + int alsa;
> > + int dvb;
> > +
> > + /* Sub-device specifications */
> > + /* Nothing needed yet */
> > + __u8 raw[64];
> > + };
> > +};
>
> Should this be a packed struct?
Why ? :-) Packed struct are most useful when they need to match hardware
structures or network protocols. Packing a structure can generate unaligned
fields, which are bad performance-wise.
--
Regards,
Laurent Pinchart
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