From: Phillip Michael Jordan phil@philjordan.eu
The support for the SB Extigy's remote seems to be broken in all recent ALSA versions, including 1.0.17. The driver detects the event correctly, then submits a URB to query the RC code. On the Extigy, the URB is submitted with a length of 2 bytes. My hardware, however, only replies with 1 byte, containing the correct RC button code. The current implementation discards this as being too short. (line 1784 of usbmixer.c)
This patch specifies a "minimum packet length" in the remote control configuration. I've left the values for the Audigy 2/Live! the same as the packet length, as I'm assuming the existing code works with them. (I don't have the hardware to confirm) This fixes the Extigy RC support, e.g. for use with Lirc.
Signed-off-by: Phillip Michael Jordan phil@philjordan.eu
---
An alternative, simpler fix would be to change the check on line 1784 to
if (urb->status < 0 || urb->actual_length < rc->offset + rc->length)
On the Extigy, this works out the same as the fix proposed in the patch (urb->actual_length < 1), but I have no idea how this would behave with the other types of hardware.
Comments & suggestions welcome!
phil
--- a/sound/usb/usbmixer.c 2008-08-05 10:30:12.729535006 +0200 +++ b/sound/usb/usbmixer.c 2008-08-05 10:29:23.497533626 +0200 @@ -59,12 +59,13 @@ static const struct rc_config { u8 offset; u8 length; u8 packet_length; + u8 min_packet_length; /* minimum accepted length of the URB result */ u8 mute_mixer_id; u32 mute_code; } rc_configs[] = { - { USB_ID(0x041e, 0x3000), 0, 1, 2, 18, 0x0013 }, /* Extigy */ - { USB_ID(0x041e, 0x3020), 2, 1, 6, 18, 0x0013 }, /* Audigy 2 NX */ - { USB_ID(0x041e, 0x3040), 2, 2, 6, 2, 0x6e91 }, /* Live! 24-bit */ + { USB_ID(0x041e, 0x3000), 0, 1, 2, 1, 18, 0x0013 }, /* Extigy */ + { USB_ID(0x041e, 0x3020), 2, 1, 6, 6, 18, 0x0013 }, /* Audigy 2 NX */ + { USB_ID(0x041e, 0x3040), 2, 2, 6, 6, 2, 0x6e91 }, /* Live! 24-bit */ };
struct usb_mixer_interface { @@ -1781,7 +1782,7 @@ static void snd_usb_soundblaster_remote_ const struct rc_config *rc = mixer->rc_cfg; u32 code;
- if (urb->status < 0 || urb->actual_length < rc->packet_length) + if (urb->status < 0 || urb->actual_length < rc->min_packet_length) return;
code = mixer->rc_buffer[rc->offset];