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From: Takashi Sakamoto <o-takashi@sakamocchi.jp>
To: clemens@ladisch.de, tiwai@suse.de, perex@perex.cz
Cc: alsa-devel@alsa-project.org, ffado-devel@lists.sf.net
Subject: [PATCH 18/39] firewire-lib: Add a fallback at RCODE_CANCELLED
Date: Wed,  5 Mar 2014 19:48:06 +0900
Message-ID: <1394016507-15761-19-git-send-email-o-takashi@sakamocchi.jp> (raw)
In-Reply-To: <1394016507-15761-1-git-send-email-o-takashi@sakamocchi.jp>

I confirm that some devices often send no response against driver's
request even if the devices handle the request. In this case, drivers
should not retry the request because it's not clear whether the devices
already handled an operation of the request or not. The second request
may bring errors or make no sence if the request was handled.

This patch adds a flag, FW_RETURN_TIMEOUT, for snd_fw_transaction().
With this flag, this function returns -ETIMEOUT when fw_run_transaction()
returns RCODE_CALCELLED.

For FCP, this patch modifies fcp_avc_transaction() with this flag. The
-ETIMEDOUT is handled as success. Linux Firewire Subsystem currently gives
2,000msec for default timeout (See DEFAULT_SPLIT_TIMEOUT in core-card.c).
firewire-lib gives 125msec for wait_event_timeout(). As a result, in worst
case that all of three retries are timeout and devices don't send responses,
fcp_avc_transaction() returns 6sec later ((2000 + 125) msec * 3 times). But
this is rare.

For CMP, this patch modifies pcr_modify() with this flag. The -ETIMEOUT
generates another read transaction to check current value of PCR. If this
read transaction returns errors, then pcr_modify() returns the error code.
---
 sound/firewire/cmp.c | 23 +++++++++++++++++++++--
 sound/firewire/fcp.c |  5 +++--
 sound/firewire/lib.c |  6 +++++-
 sound/firewire/lib.h |  1 +
 4 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/sound/firewire/cmp.c b/sound/firewire/cmp.c
index a8199fd..73f5f26 100644
--- a/sound/firewire/cmp.c
+++ b/sound/firewire/cmp.c
@@ -89,13 +89,32 @@ static int pcr_modify(struct cmp_connection *c,
 		err = snd_fw_transaction(
 				c->resources.unit, TCODE_LOCK_COMPARE_SWAP,
 				get_offset(c, false), buffer, 8,
-				FW_FIXED_GENERATION | c->resources.generation);
+				FW_FIXED_GENERATION | c->resources.generation |
+				FW_RETURN_TIMEOUT);
 
 		if (err < 0) {
 			if (err == -EAGAIN &&
 			    bus_reset_handling == SUCCEED_ON_BUS_RESET)
 				err = 0;
-			return err;
+
+			if (err != -ETIMEDOUT)
+				return err;
+
+			/* Check current PCR. */
+			err = snd_fw_transaction(
+				c->resources.unit, TCODE_READ_QUADLET_REQUEST,
+				get_offset(c, false), buffer, 4,
+				FW_FIXED_GENERATION | c->resources.generation);
+			if (err < 0)
+				return err;
+
+			/* The lock transaction may be failed, retry */
+			if (buffer[0] != buffer[1]) {
+				buffer[0] = c->last_pcr_value;
+				continue;
+			}
+
+			break;
 		}
 
 		if (buffer[0] == old_arg) /* success? */
diff --git a/sound/firewire/fcp.c b/sound/firewire/fcp.c
index e903ddb..6fc813f 100644
--- a/sound/firewire/fcp.c
+++ b/sound/firewire/fcp.c
@@ -245,8 +245,9 @@ int fcp_avc_transaction(struct fw_unit *unit,
 					  : TCODE_WRITE_BLOCK_REQUEST;
 		ret = snd_fw_transaction(t.unit, tcode,
 					 CSR_REGISTER_BASE + CSR_FCP_COMMAND,
-					 (void *)command, command_size, 0);
-		if (ret < 0)
+					 (void *)command, command_size,
+					 FW_RETURN_TIMEOUT);
+		if ((ret < 0) && (ret != -ETIMEDOUT))
 			break;
 
 		wait_event_timeout(t.wait, t.state != STATE_PENDING,
diff --git a/sound/firewire/lib.c b/sound/firewire/lib.c
index 7409edb..de42748 100644
--- a/sound/firewire/lib.c
+++ b/sound/firewire/lib.c
@@ -22,7 +22,7 @@
  * @length: length of @buffer
  * @flags: use %FW_FIXED_GENERATION and add the generation value to attempt the
  *         request only in that generation; use %FW_QUIET to suppress error
- *         messages
+ *         messages; use %FW_RETURN_TIMEOUT to avoid retry at RCODE_CANCELLED
  *
  * Submits an asynchronous request to the target device, and waits for the
  * response.  The node ID and the current generation are derived from @unit.
@@ -53,6 +53,10 @@ int snd_fw_transaction(struct fw_unit *unit, int tcode,
 		if (rcode == RCODE_GENERATION && (flags & FW_FIXED_GENERATION))
 			return -EAGAIN;
 
+		/* timeout */
+		if ((rcode == RCODE_CANCELLED) && (flags & FW_RETURN_TIMEOUT))
+			return -ETIMEDOUT;
+
 		if (rcode_is_permanent_error(rcode) || ++tries >= 3) {
 			if (!(flags & FW_QUIET))
 				dev_err(&unit->device,
diff --git a/sound/firewire/lib.h b/sound/firewire/lib.h
index 02cfabc..b8ea90b 100644
--- a/sound/firewire/lib.h
+++ b/sound/firewire/lib.h
@@ -9,6 +9,7 @@ struct fw_unit;
 #define FW_GENERATION_MASK	0x00ff
 #define FW_FIXED_GENERATION	0x0100
 #define FW_QUIET		0x0200
+#define FW_RETURN_TIMEOUT	0x0400
 
 int snd_fw_transaction(struct fw_unit *unit, int tcode,
 		       u64 offset, void *buffer, size_t length,
-- 
1.8.3.2

  parent reply index

Thread overview: 84+ 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
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   ` Takashi Sakamoto [this message]
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 18/39] firewire-lib: Add a fallback at RCODE_CANCELLED Takashi Sakamoto
2014-02-28 20:25   ` Stefan Richter
2014-02-28 20:39     ` Stefan Richter
2014-03-01  3:18     ` Takashi Sakamoto
2014-03-01 10:10       ` Stefan Richter
2014-03-01 12:22         ` Takashi Sakamoto
2014-03-01 14:20           ` Stefan Richter
2014-03-01 10:34   ` Stefan Richter
2014-03-01 12:23     ` Takashi Sakamoto

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