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From: Clemens Ladisch <clemens@ladisch.de>
To: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Cc: tiwai@suse.de, alsa-devel@alsa-project.org, ffado-devel@lists.sf.net
Subject: Re: [PATCH 08/39] firewire-lib: Add support for duplex streams synchronization in blocking mode
Date: Sun, 09 Mar 2014 21:55:06 +0100
Message-ID: <531CD52A.1040902@ladisch.de> (raw)
In-Reply-To: <1394016507-15761-9-git-send-email-o-takashi@sakamocchi.jp>

Takashi Sakamoto wrote:
> Generally, the devices can synchronize to handle 'presentation timestamp'
> in CIP packets. This commit adds functionality to pick up this timestamp from
> in-packets transmitted by the device, then use it for out packets.
>
> In current implementation, this module generated the timestamp by itself. This
> is 'SYT Match' mode. Then this drive acts as synchronization master. This
> commit allows this module to act as synchronization slave.
>
> This commit restricts this mechanism is only available in blocking mode because
> handling the timestamp in non-blocking mode is more complicated than in
> blocking mode.

> +++ b/sound/firewire/amdtp.c
> @@ -72,6 +73,10 @@ int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
> +	s->sync_slave = ERR_PTR(-1);

This pointer does not report any actual error code either.

> @@ -626,7 +631,7 @@ static void handle_out_packet(struct amdtp_stream *s, unsigned int syt)
>  {
> -	struct snd_pcm_substream *pcm;
> +	struct snd_pcm_substream *pcm = NULL;

Why this change in this patch?

> @@ -768,6 +773,15 @@ static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
> +		/* Process sync slave stream */
> +		if ((s->flags & CIP_BLOCKING) &&
> +		    (s->flags & CIP_SYNC_TO_DEVICE) &&
> +		    s->sync_slave->callbacked) {

It might be easier to check just s->sync_slave instead of multiple flags.


> +	/* when sync to device, flush the packets for slave stream */
> +	if ((s->flags & CIP_BLOCKING) &&
> +	    (s->flags & CIP_SYNC_TO_DEVICE) && s->sync_slave->callbacked)

Same here.

> +/* this is executed one time */
> +static void amdtp_stream_callback(struct fw_iso_context *context, u32 cycle,

This name is rather generic; this is not "the" callback, but the
"initial" or "first" callback.

> ...
> +	return;
> +}

This is not necessary here.

> +static inline void amdtp_stream_set_sync(enum cip_flags sync_mode,
> +					 struct amdtp_stream *master,
> +					 struct amdtp_stream *slave)
> +{
> +	/* clear sync flag */
> +	master->flags &= ~CIP_SYNC_TO_DEVICE;
> +	slave->flags &= ~CIP_SYNC_TO_DEVICE;

This needs to be done only if sync_mode != CIP_SYNC_TO_DEVICE.


Regards,
Clemens

  reply index

Thread overview: 76+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <5316963F.1000206@sakamocchi.jp>
2014-03-05  6:14 ` [GIT PULL v2] Enhancement of support for Firewire devices Takashi Iwai
2014-03-05 11:00   ` Takashi Sakamoto
2014-03-05 11:09     ` Takashi Iwai
2014-03-05 11:23       ` Takashi Sakamoto
2014-03-05 10:47 ` [GIT PULL][PATCH 00/39 " Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 01/39] firewire-lib: Rename functions, structure, member for AMDTP Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 02/39] firewire-lib: Add macros instead of fixed value " Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 03/39] firewire-lib: Add 'direction' member to 'amdtp_stream' structure Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 04/39] firewire-lib: Split some codes into functions to reuse for both streams Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 05/39] firewire-lib: Add support for AMDTP in-stream and PCM capture Takashi Sakamoto
2014-03-09 20:37     ` Clemens Ladisch
2014-03-10  3:55       ` Takashi Sakamoto
2014-03-12  2:00       ` Takashi Sakamoto
2014-03-14 13:50       ` Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 06/39] firewire-lib: Add support for MIDI capture/playback Takashi Sakamoto
2014-03-09 20:48     ` Clemens Ladisch
2014-03-10  4:13       ` Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 07/39] firewire-lib: Give syt value as parameter to handle_out_packet() Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 08/39] firewire-lib: Add support for duplex streams synchronization in blocking mode Takashi Sakamoto
2014-03-09 20:55     ` Clemens Ladisch [this message]
2014-03-10 12:21       ` Takashi Sakamoto
2014-03-05 10:47   ` [PATCH 09/39] firewire-lib: Add sort function for transmitted packet Takashi Sakamoto
2014-03-09 21:07     ` Clemens Ladisch
2014-03-10 13:29       ` Takashi Sakamoto
2014-03-11  8:11         ` Clemens Ladisch
2014-03-12  1:23           ` Takashi Sakamoto
2014-03-12  7:21             ` Takashi Iwai
2014-03-05 10:47   ` [PATCH 10/39] firewire-lib: Add transfer delay to synchronized duplex streams Takashi Sakamoto
2014-03-09 21:13     ` Clemens Ladisch
2014-03-10 13:43       ` Takashi Sakamoto
2014-03-11  8:13         ` Clemens Ladisch
2014-03-05 10:47   ` [PATCH 11/39] firewire-lib: Add support for channel mapping Takashi Sakamoto
2014-03-09 21:20     ` Clemens Ladisch
2014-03-10 12:28       ` Takashi Sakamoto
2014-03-10 12:58         ` Takashi Sakamoto
2014-03-11  8:23         ` Clemens Ladisch
2014-03-11 16:03           ` Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 12/39] firewire-lib: Rename macros, variables and functions for CMP Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 13/39] firewire-lib: Add 'direction' member to 'cmp_connection' structure Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 14/39] firewire-lib: Add handling output connection by CMP Takashi Sakamoto
2014-03-09 21:27     ` Clemens Ladisch
2014-03-10 12:30       ` Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 15/39] firewire-lib: Add a new function to check others' connection Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 16/39] firewire-lib: Add some AV/C general commands Takashi Sakamoto
2014-03-09 21:32     ` Clemens Ladisch
2014-03-10 12:46       ` Takashi Sakamoto
2014-03-14 14:10       ` Takashi Sakamoto
2014-03-14 22:18         ` Clemens Ladisch
2014-03-05 10:48   ` [PATCH 17/39] firewire-lib: Add quirks for Fireworks Takashi Sakamoto
2014-03-09 21:39     ` Clemens Ladisch
2014-03-10 12:40       ` Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 18/39] firewire-lib: Add a fallback at RCODE_CANCELLED Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 19/39] fireworks: Add skelton for Fireworks based devices Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 20/39] fireworks: Add transaction and some commands Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 21/39] fireworks: Add connection and stream management Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 22/39] fireworks: Add proc interface for debugging purpose Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 23/39] fireworks: Add MIDI interface Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 24/39] fireworks: Add PCM interface Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 25/39] fireworks: Add hwdep interface Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 26/39] fireworks: Add command/response functionality into " Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 27/39] bebob: Add skelton for BeBoB based devices Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 28/39] bebob: Add commands and connections/streams management Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 29/39] bebob: Add proc interface for debugging purpose Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 30/39] bebob: Add MIDI interface Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 31/39] bebob: Add PCM interface Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 32/39] bebob: Add hwdep interface Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 33/39] bebob: Prepare for device specific operations Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 34/39] bebob: Add support for Terratec PHASE, EWS series and Aureon Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 35/39] bebob: Add support for Yamaha GO series Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 36/39] bebob: Add support for Focusrite Saffire/SaffirePro series Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 37/39] bebob: Add support for M-Audio usual Firewire series Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 38/39] bebob: Add support for M-Audio special " Takashi Sakamoto
2014-03-05 10:48   ` [PATCH 39/39] bebob: Send a cue to load firmware for M-Audio " Takashi Sakamoto
2014-03-07 11:44 ` [GIT PULL v2] Enhancement of support for Firewire devices Takashi Iwai
2014-03-07 14:46   ` Clemens Ladisch
2014-02-28  3:27 [GIT PULL][PATCH 00/39] " Takashi Sakamoto
2014-02-28  3:27 ` [PATCH 08/39] firewire-lib: Add support for duplex streams synchronization in blocking mode Takashi Sakamoto

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