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authorTakashi Sakamoto <o-takashi@sakamocchi.jp>2014-04-25 17:45:30 +0400
committerTakashi Iwai <tiwai@suse.de>2014-05-26 16:33:10 +0400
commit9b1ee0b2cb8bffdbb3003b1d5205f3ae0592c15a (patch)
tree31124c27fddbaca390e63ebb47174ade02952a89
parenta2b2a7798fb6a5c639189e5c8f608a56fdc7a222 (diff)
downloadlinux-9b1ee0b2cb8bffdbb3003b1d5205f3ae0592c15a.tar.xz
ALSA: firewire/bebob: Add a workaround for M-Audio special Firewire series
In post commit, a quirk of this firmware about transactions is reported. This commit apply a workaround for this quirk. They often fail transactions due to gap_count mismatch. This state is changed by generating bus reset. The fw_schedule_bus_reset() is an exported symbol in firewire-core. But there are no header for public. This commit moves its prototype from drivers/firewire/core.h to include/linux/firewire.h. This mismatch still affects bus management before generating this bus reset. It still takes a time to call driver's probe() because transactions are still often failed. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
-rw-r--r--drivers/firewire/core.h1
-rw-r--r--include/linux/firewire.h3
-rw-r--r--sound/firewire/bebob/bebob.c32
-rw-r--r--sound/firewire/bebob/bebob.h1
4 files changed, 32 insertions, 5 deletions
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index c98764aeeec6..870044e82316 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -118,7 +118,6 @@ int fw_card_add(struct fw_card *card,
u32 max_receive, u32 link_speed, u64 guid);
void fw_core_remove_card(struct fw_card *card);
int fw_compute_block_crc(__be32 *block);
-void fw_schedule_bus_reset(struct fw_card *card, bool delayed, bool short_reset);
void fw_schedule_bm_work(struct fw_card *card, unsigned long delay);
/* -cdev */
diff --git a/include/linux/firewire.h b/include/linux/firewire.h
index c3683bdf28fe..d4b7683c722d 100644
--- a/include/linux/firewire.h
+++ b/include/linux/firewire.h
@@ -367,6 +367,9 @@ static inline int fw_stream_packet_destination_id(int tag, int channel, int sy)
return tag << 14 | channel << 8 | sy;
}
+void fw_schedule_bus_reset(struct fw_card *card, bool delayed,
+ bool short_reset);
+
struct fw_descriptor {
struct list_head link;
size_t length;
diff --git a/sound/firewire/bebob/bebob.c b/sound/firewire/bebob/bebob.c
index e1dd4219ea6c..31b96b7264cf 100644
--- a/sound/firewire/bebob/bebob.c
+++ b/sound/firewire/bebob/bebob.c
@@ -247,10 +247,26 @@ bebob_probe(struct fw_unit *unit,
if (err < 0)
goto error;
- err = snd_card_register(card);
- if (err < 0) {
- snd_bebob_stream_destroy_duplex(bebob);
- goto error;
+ if (!bebob->maudio_special_quirk) {
+ err = snd_card_register(card);
+ if (err < 0) {
+ snd_bebob_stream_destroy_duplex(bebob);
+ goto error;
+ }
+ } else {
+ /*
+ * This is a workaround. This bus reset seems to have an effect
+ * to make devices correctly handling transactions. Without
+ * this, the devices have gap_count mismatch. This causes much
+ * failure of transaction.
+ *
+ * Just after registration, user-land application receive
+ * signals from dbus and starts I/Os. To avoid I/Os till the
+ * future bus reset, registration is done in next update().
+ */
+ bebob->deferred_registration = true;
+ fw_schedule_bus_reset(fw_parent_device(bebob->unit)->card,
+ false, true);
}
dev_set_drvdata(&unit->device, bebob);
@@ -273,6 +289,14 @@ bebob_update(struct fw_unit *unit)
fcp_bus_reset(bebob->unit);
snd_bebob_stream_update_duplex(bebob);
+
+ if (bebob->deferred_registration) {
+ if (snd_card_register(bebob->card) < 0) {
+ snd_bebob_stream_destroy_duplex(bebob);
+ snd_card_free(bebob->card);
+ }
+ bebob->deferred_registration = false;
+ }
}
static void bebob_remove(struct fw_unit *unit)
diff --git a/sound/firewire/bebob/bebob.h b/sound/firewire/bebob/bebob.h
index 4a54e746c5c6..91b26b0c649a 100644
--- a/sound/firewire/bebob/bebob.h
+++ b/sound/firewire/bebob/bebob.h
@@ -109,6 +109,7 @@ struct snd_bebob {
/* for M-Audio special devices */
void *maudio_special_quirk;
+ bool deferred_registration;
};
static inline int