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Commit 9b1ee0b2 authored by Takashi Sakamoto's avatar Takashi Sakamoto Committed by Takashi Iwai
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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: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
parent a2b2a779

drivers/firewire/core.h

+0 −1
Original line number Diff line number Diff line
@@ -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 */

include/linux/firewire.h

+3 −0
Original line number Diff line number Diff line
@@ -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;

sound/firewire/bebob/bebob.c

+28 −4
Original line number Diff line number Diff line
@@ -247,11 +247,27 @@ bebob_probe(struct fw_unit *unit, 
	if (err < 0)

		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);

end:
@@ -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)

sound/firewire/bebob/bebob.h

+1 −0
Original line number Diff line number Diff line
@@ -109,6 +109,7 @@ struct snd_bebob { 


	/* for M-Audio special devices */

	void *maudio_special_quirk;

	bool deferred_registration;

};



static inline int