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authorClemens Ladisch <clemens@ladisch.de>2012-10-31 16:35:30 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-12-03 11:37:57 -0800
commit0ef24e01e9a96a936f893e6abfa5ff89a4af648a (patch)
tree840288fa5b118253461a0ae6bcb9349fc280ffba
parentbba14defc28e372727bf98d63d2bee9efbd4bda2 (diff)
downloadlinux-linaro-stable-0ef24e01e9a96a936f893e6abfa5ff89a4af648a.tar.gz
ALSA: ua101, usx2y: fix broken MIDI output
commit e99ddfde6ae0dd2662bb40435696002b590e4057 upstream. Commit 88a8516a2128 (ALSA: usbaudio: implement USB autosuspend) added autosuspend code to all files making up the snd-usb-audio driver. However, midi.c is part of snd-usb-lib and is also used by other drivers, not all of which support autosuspend. Thus, calls to usb_autopm_get_interface() could fail, and this unexpected error would result in the MIDI output being completely unusable. Make it work by ignoring the error that is expected with drivers that do not support autosuspend. Reported-by: Colin Fletcher <colin.m.fletcher@googlemail.com> Reported-by: Devin Venable <venable.devin@gmail.com> Reported-by: Dr Nick Bailey <nicholas.bailey@glasgow.ac.uk> Reported-by: Jannis Achstetter <jannis_achstetter@web.de> Reported-by: Rui Nuno Capela <rncbc@rncbc.org> Cc: Oliver Neukum <oliver@neukum.org> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--sound/usb/midi.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index c83f6143c0eb..eeefbce3873c 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -148,6 +148,7 @@ struct snd_usb_midi_out_endpoint {
struct snd_usb_midi_out_endpoint* ep;
struct snd_rawmidi_substream *substream;
int active;
+ bool autopm_reference;
uint8_t cable; /* cable number << 4 */
uint8_t state;
#define STATE_UNKNOWN 0
@@ -1076,7 +1077,8 @@ static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
return -ENXIO;
}
err = usb_autopm_get_interface(umidi->iface);
- if (err < 0)
+ port->autopm_reference = err >= 0;
+ if (err < 0 && err != -EACCES)
return -EIO;
substream->runtime->private_data = port;
port->state = STATE_UNKNOWN;
@@ -1087,9 +1089,11 @@ static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
{
struct snd_usb_midi* umidi = substream->rmidi->private_data;
+ struct usbmidi_out_port *port = substream->runtime->private_data;
substream_open(substream, 0);
- usb_autopm_put_interface(umidi->iface);
+ if (port->autopm_reference)
+ usb_autopm_put_interface(umidi->iface);
return 0;
}