[alsa-devel] [PATCH 0/2 v2] ALSA: oxfw: implement retries for scs1x at transaction failure
Hi,
This patchset updates my former post below. Changes are just adding my sign (I forgot it...) and improvements of commit messages.
[alsa-devel] [PATCH 0/2] ALSA: oxfw: implement retries for scs1x at transaction failure http://mailman.alsa-project.org/pipermail/alsa-devel/2016-February/104579.ht...
In thread of the post, I got some comments about work to extend ALSA rawmidi core. I've investigated it in a few days ago and realized that it may not so light work, mainly because of a lack of unified state management[0].
In this development cycle, I'd like to give it up and use my time for the other work within my plan for the cycle. Please just apply these two patches.
[0] In short, the state management is understandable for developers who can understand it, and I'm not.
Regards
Takashi Sakamoto (2): ALSA: oxfw: retry MIDI transferring for scs1x at transaction failure ALSA: oxfw: discontinue MIDI substream for scs1x at transaction failure
sound/firewire/oxfw/oxfw-scs1x.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-)
Currently, ALSA oxfw driver has a TODO to retry MIDI transferring at transaction failure.
This commit achieves it. Current implementation uses snd_rawmidi_transmit() to transfer messages, thus the target MIDI messages are not in buffer when transaction failure is detected. Although we cannot use a pair of snd_rawmidi_transmit_peek() and snd_ramwidi_transmit_ack(), the messages are still in scs1x specific structure and the data is available for retries.
This commit adds a member to the structure for the length of buffered messages, and uses the value again at retries.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/oxfw/oxfw-scs1x.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/sound/firewire/oxfw/oxfw-scs1x.c b/sound/firewire/oxfw/oxfw-scs1x.c index f7ac124..72446ac 100644 --- a/sound/firewire/oxfw/oxfw-scs1x.c +++ b/sound/firewire/oxfw/oxfw-scs1x.c @@ -31,6 +31,7 @@ struct fw_scs1x { u8 buffer[HSS1394_MAX_PACKET_SIZE]; bool transaction_running; struct fw_transaction transaction; + unsigned int transaction_bytes; struct fw_device *fw_dev; };
@@ -125,8 +126,8 @@ static void scs_write_callback(struct fw_card *card, int rcode, { struct fw_scs1x *scs = callback_data;
- if (rcode == RCODE_GENERATION) - ; /* TODO: retry this packet */ + if (rcode != RCODE_GENERATION) + scs->transaction_bytes = 0;
scs->transaction_running = false; schedule_work(&scs->work); @@ -183,6 +184,9 @@ static void scs_output_work(struct work_struct *work) return; }
+ if (scs->transaction_bytes > 0) + goto retry; + i = scs->output_bytes; for (;;) { if (snd_rawmidi_transmit(stream, &byte, 1) != 1) { @@ -253,13 +257,16 @@ static void scs_output_work(struct work_struct *work) scs->output_bytes = 1; scs->output_escaped = false;
+ scs->transaction_bytes = i; +retry: scs->transaction_running = true; generation = scs->fw_dev->generation; smp_rmb(); /* node_id vs. generation */ fw_send_request(scs->fw_dev->card, &scs->transaction, TCODE_WRITE_BLOCK_REQUEST, scs->fw_dev->node_id, generation, scs->fw_dev->max_speed, HSS1394_ADDRESS, - scs->buffer, i, scs_write_callback, scs); + scs->buffer, scs->transaction_bytes, + scs_write_callback, scs); }
static int midi_capture_open(struct snd_rawmidi_substream *stream) @@ -309,6 +316,7 @@ static void midi_playback_trigger(struct snd_rawmidi_substream *stream, int up) scs->output_bytes = 1; scs->output_escaped = false; scs->output_idle = false; + scs->transaction_bytes = 0;
ACCESS_ONCE(scs->output) = stream; schedule_work(&scs->work);
With a previous commit, ALSA oxfw driver retries transferring MIDI messages at transaction failure for scs1x. On the other hand, there're fatal transaction error. Then, no MIDI messages reach to the unit anymore. In this case, MIDI substream should be terminated.
This commit stops MIDI transmission after the fatal error occurs. Unfortunately, unlike ALSA PCM functionality, ALSA rawmidi core has no feature to discontinue MIDI substream runtime in kernel side, thus this commit just stops MIDI transmission without notifying it to userspace.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/oxfw/oxfw-scs1x.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/sound/firewire/oxfw/oxfw-scs1x.c b/sound/firewire/oxfw/oxfw-scs1x.c index 72446ac..f897c98 100644 --- a/sound/firewire/oxfw/oxfw-scs1x.c +++ b/sound/firewire/oxfw/oxfw-scs1x.c @@ -32,6 +32,7 @@ struct fw_scs1x { bool transaction_running; struct fw_transaction transaction; unsigned int transaction_bytes; + bool error; struct fw_device *fw_dev; };
@@ -126,8 +127,13 @@ static void scs_write_callback(struct fw_card *card, int rcode, { struct fw_scs1x *scs = callback_data;
- if (rcode != RCODE_GENERATION) - scs->transaction_bytes = 0; + if (!rcode_is_permanent_error(rcode)) { + /* Don't retry for this data. */ + if (rcode == RCODE_COMPLETE) + scs->transaction_bytes = 0; + } else { + scs->error = true; + }
scs->transaction_running = false; schedule_work(&scs->work); @@ -178,7 +184,7 @@ static void scs_output_work(struct work_struct *work) return;
stream = ACCESS_ONCE(scs->output); - if (!stream) { + if (!stream || scs->error) { scs->output_idle = true; wake_up(&scs->idle_wait); return; @@ -317,6 +323,7 @@ static void midi_playback_trigger(struct snd_rawmidi_substream *stream, int up) scs->output_escaped = false; scs->output_idle = false; scs->transaction_bytes = 0; + scs->error = false;
ACCESS_ONCE(scs->output) = stream; schedule_work(&scs->work);
On Wed, 24 Feb 2016 01:26:31 +0100, Takashi Sakamoto wrote:
Hi,
This patchset updates my former post below. Changes are just adding my sign (I forgot it...) and improvements of commit messages.
[alsa-devel] [PATCH 0/2] ALSA: oxfw: implement retries for scs1x at transaction failure http://mailman.alsa-project.org/pipermail/alsa-devel/2016-February/104579.ht...
In thread of the post, I got some comments about work to extend ALSA rawmidi core. I've investigated it in a few days ago and realized that it may not so light work, mainly because of a lack of unified state management[0].
In this development cycle, I'd like to give it up and use my time for the other work within my plan for the cycle. Please just apply these two patches.
[0] In short, the state management is understandable for developers who can understand it, and I'm not.
Regards
Takashi Sakamoto (2): ALSA: oxfw: retry MIDI transferring for scs1x at transaction failure ALSA: oxfw: discontinue MIDI substream for scs1x at transaction failure
Applied both now. Thanks.
Takashi
On Feb 25 2016 00:33, Takashi Iwai wrote:
On Wed, 24 Feb 2016 01:26:31 +0100, Takashi Sakamoto wrote:
Hi,
This patchset updates my former post below. Changes are just adding my sign (I forgot it...) and improvements of commit messages.
[alsa-devel] [PATCH 0/2] ALSA: oxfw: implement retries for scs1x at transaction failure http://mailman.alsa-project.org/pipermail/alsa-devel/2016-February/104579.ht...
In thread of the post, I got some comments about work to extend ALSA rawmidi core. I've investigated it in a few days ago and realized that it may not so light work, mainly because of a lack of unified state management[0].
In this development cycle, I'd like to give it up and use my time for the other work within my plan for the cycle. Please just apply these two patches.
[0] In short, the state management is understandable for developers who can understand it, and I'm not.
Regards
Takashi Sakamoto (2): ALSA: oxfw: retry MIDI transferring for scs1x at transaction failure ALSA: oxfw: discontinue MIDI substream for scs1x at transaction failure
Applied both now. Thanks.
Thanks.
ALSA rawmidi core handles substreams for both directions, therefore state management may not so simple as we expected (at least, for driver based on packet streaming such as IEC 61883-1/6, there're more items to be considered. So as USB MIDI Device class, too, I think). I'd like to schedule the work to next developing cycle for Linux 4.7 or later.
Regards
Takashi Sakamoto
participants (2)
-
Takashi Iwai -
Takashi Sakamoto