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authorDaniel Mack <zonque@gmail.com>2012-09-04 10:23:07 +0200
committerTakashi Iwai <tiwai@suse.de>2012-09-04 11:31:14 +0200
commit2b58fd5b3193fd3af3d15114d95706087d25a7fe (patch)
tree929c51bd48ee1637f963fa520bf31eee04927861 /sound/usb/endpoint.c
parentALSA: USB: Support for (original) Xbox Communicator (diff)
downloadlinux-2b58fd5b3193fd3af3d15114d95706087d25a7fe.tar.xz
linux-2b58fd5b3193fd3af3d15114d95706087d25a7fe.zip
ALSA: snd-usb: Add quirks for Playback Designs devices
Playback Designs' USB devices have some hardware limitations on their USB interface. In particular: - They need a 20ms delay after each class compliant request as the hardware ACKs the USB packets before the device is actually ready for the next command. Sending data immediately will result in buffer overflows in the hardware. - The devices send bogus feedback data at the start of each stream which confuse the feedback format auto-detection. This patch introduces a new quirks hook that is called after each control packet and which adds a delay for all devices that match Playback Designs' USB VID for now. In addition, it adds a counter to snd_usb_endpoint to drop received packets on the floor. Another new quirks function that is called once an endpoint is started initializes that counter for these devices on their sync endpoint. Signed-off-by: Daniel Mack <zonque@gmail.com> Reported-and-tested-by: Andreas Koch <andreas@akdesigninc.com> Supported-by: Demian Martin <demianm_1@yahoo.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/endpoint.c')
-rw-r--r--sound/usb/endpoint.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index c41181202688..94b08a6087a3 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -31,6 +31,7 @@
#include "card.h"
#include "endpoint.h"
#include "pcm.h"
+#include "quirks.h"
#define EP_FLAG_ACTIVATED 0
#define EP_FLAG_RUNNING 1
@@ -170,6 +171,11 @@ static void retire_inbound_urb(struct snd_usb_endpoint *ep,
{
struct urb *urb = urb_ctx->urb;
+ if (unlikely(ep->skip_packets > 0)) {
+ ep->skip_packets--;
+ return;
+ }
+
if (ep->sync_slave)
snd_usb_handle_sync_urb(ep->sync_slave, ep, urb);
@@ -825,6 +831,8 @@ int snd_usb_endpoint_start(struct snd_usb_endpoint *ep)
ep->unlink_mask = 0;
ep->phase = 0;
+ snd_usb_endpoint_start_quirk(ep);
+
/*
* If this endpoint has a data endpoint as implicit feedback source,
* don't start the urbs here. Instead, mark them all as available,