On Thu, Apr 05, 2018 at 04:37:14PM -0500, Pierre-Louis Bossart wrote:
> On 4/5/18 11:48 AM, Vinod Koul wrote:
> >+SoundWire stream states
> >+-----------------------
> >+
> >+Below shows the SoundWire stream states and state transition diagram. ::
> >+
> >+ +-----------+ +------------+ +----------+ +----------+
> >+ | ALLOCATED +---->| CONFIGURED +---->| PREPARED +---->| ENABLED |
> >+ | STATE | | STATE | | STATE | | STATE |
> >+ +-----------+ +------------+ +----------+ +----+-----+
> >+ ^
> >+ |
> >+ |
> >+ v
> >+ +----------+ +------------+ +----+-----+
> >+ | RELEASED |<----------+ DEPREPARED |<-------+ DISABLED |
> >+ | STATE | | STATE | | STATE |
> >+ +----------+ +------------+ +----------+
> >+
>
> Patch 2 describes the states as below:
>
> +enum sdw_stream_state {
> + SDW_STREAM_RELEASED = 0,
> + SDW_STREAM_ALLOCATED = 1,
> + SDW_STREAM_CONFIGURED = 2,
> + SDW_STREAM_PREPARED = 3,
> + SDW_STREAM_ENABLED = 4,
> + SDW_STREAM_DISABLED = 5,
> + SDW_STREAM_DEPREPARED = 6,
>
> which isn't the same picture as the ascii art above. The RELEASED state is
> the starting point, and there's an arrow missing from RELEASED to ALLOCATED.
The enumerator describes the values given for each state. That has no
relation whatsoever to state transitions allowed. I don't recall why people
made SDW_STREAM_RELEASED as Zero, it could very well have been 7 and nothing
changes in diagram.
Now in the last review I did mention to you that there is NO transition
between RELEASED and ALLOCATED, hence no arrow can be made.
Your point on initial state is not right. I can we go ahead and do a
kmalloc() instead of current kzalloc() for the structure which would make
stream state from garbage/uninitialized to ALLOCATED and eventually finally
into RELEASED and it being freed. See no move between ALLOCATED and
RELEASED!
--
~Vinod
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