Commit d52bb3da authored by Takashi Sakamoto's avatar Takashi Sakamoto
Browse files

firewire: core: handle device quirk of TASCAM FW-1884/FW-1804/FW-1082 

TASCAM FW-1884/FW-1804/FW-1082 is too lazy to repspond to asynchronous
request at S400. The asynchronous transaction often results in timeout.
This is a problematic quirk.

This commit adds support for the quirk. When identifying the new quirk
flag, then the transaction speed is configured at S200.

Link: https://lore.kernel.org/r/20251018035532.287124-4-o-takashi@sakamocchi.jp


Signed-off-by: default avatarTakashi Sakamoto <o-takashi@sakamocchi.jp>
parent 55b4e903

drivers/firewire/core-device.c

+17 −1
Original line number Diff line number Diff line
@@ -571,6 +571,14 @@ static const struct entry_match motu_audio_express_matches[] = { 
	{ 8, 0x17104800 },

};



static const struct entry_match tascam_fw_series_matches[] = {

	{ 1, 0x0300022e },

	{ 3, 0x8d000006 },

	{ 4, 0xd1000001 },

	{ 6, 0x1200022e },

	{ 8, 0xd4000004 },

};



static int detect_quirks_by_root_directory(const u32 *root_directory, unsigned int length)

{

	static const struct {
@@ -583,6 +591,11 @@ static int detect_quirks_by_root_directory(const u32 *root_directory, unsigned i 
			.matches = motu_audio_express_matches,

			.match_count = ARRAY_SIZE(motu_audio_express_matches),

		},

		{

			.quirk = FW_DEVICE_QUIRK_UNSTABLE_AT_S400,

			.matches = tascam_fw_series_matches,

			.match_count = ARRAY_SIZE(tascam_fw_series_matches),

		},

	};

	int quirks = 0;

	int i;
@@ -761,6 +774,9 @@ static int read_config_rom(struct fw_device *device, int generation) 
	// Just prevent from torn writing/reading.

	WRITE_ONCE(device->quirks, quirks);



	if (unlikely(quirks & FW_DEVICE_QUIRK_UNSTABLE_AT_S400))

		speed = SCODE_200;

	else

		speed = device->node->max_speed;



	// Determine the speed of

include/linux/firewire.h

+3 −0
Original line number Diff line number Diff line
@@ -179,6 +179,9 @@ enum fw_device_quirk { 


	// MOTU Audio Express transfers acknowledge packet with 0x10 for pending state.

	FW_DEVICE_QUIRK_ACK_PACKET_WITH_INVALID_PENDING_CODE = BIT(2),



	// TASCAM FW-1082/FW-1804/FW-1884 often freezes when receiving S400 packets.

	FW_DEVICE_QUIRK_UNSTABLE_AT_S400 = BIT(3),

};



enum fw_device_state {