@@ -126,7 +126,6 @@ struct snd_usb_midi {
struct snd_usb_midi_in_endpoint *in;
} endpoints[MIDI_MAX_ENDPOINTS];
unsigned long input_triggered;
- bool autopm_reference;
unsigned int opened[2];
unsigned char disconnected;
unsigned char input_running;
@@ -1040,7 +1039,6 @@ static int substream_open(struct snd_rawmidi_substream *substream, int dir,
{
struct snd_usb_midi* umidi = substream->rmidi->private_data;
struct snd_kcontrol *ctl;
- int err;
down_read(&umidi->disc_rwsem);
if (umidi->disconnected) {
@@ -1051,13 +1049,6 @@ static int substream_open(struct snd_rawmidi_substream *substream, int dir,
mutex_lock(&umidi->mutex);
if (open) {
if (!umidi->opened[0] && !umidi->opened[1]) {
- err = usb_autopm_get_interface(umidi->iface);
- umidi->autopm_reference = err >= 0;
- if (err < 0 && err != -EACCES) {
- mutex_unlock(&umidi->mutex);
- up_read(&umidi->disc_rwsem);
- return -EIO;
- }
if (umidi->roland_load_ctl) {
ctl = umidi->roland_load_ctl;
ctl->vd[0].access |= SNDRV_CTL_ELEM_ACCESS_INACTIVE;
@@ -1080,8 +1071,6 @@ static int substream_open(struct snd_rawmidi_substream *substream, int dir,
snd_ctl_notify(umidi->card,
SNDRV_CTL_EVENT_MASK_INFO, &ctl->id);
}
- if (umidi->autopm_reference)
- usb_autopm_put_interface(umidi->iface);
}
}
mutex_unlock(&umidi->mutex);
@@ -2256,6 +2245,8 @@ int snd_usbmidi_create(struct snd_card *card,
return err;
}
+ usb_autopm_get_interface_no_resume(umidi->iface);
+
list_add_tail(&umidi->list, midi_list);
return 0;
}
This is a note to let you know that I have just added a patch titled ALSA: usb-audio: disable autopm for MIDI devices to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 14758cf30ab11eee1709d816366c3933648b3703 Mon Sep 17 00:00:00 2001 From: Clemens Ladisch <clemens@ladisch.de> Date: Mon, 15 Apr 2013 15:59:51 +0200 Subject: [PATCH] ALSA: usb-audio: disable autopm for MIDI devices commit cbc200bca4b51a8e2406d4b654d978f8503d430b upstream. Commit 88a8516a2128 (ALSA: usbaudio: implement USB autosuspend) introduced autopm for all USB audio/MIDI devices. However, many MIDI devices, such as synthesizers, do not merely transmit MIDI messages but use their MIDI inputs to control other functions. With autopm, these devices would get powered down as soon as the last MIDI port device is closed on the host. Even some plain MIDI interfaces could get broken: they automatically send Active Sensing messages while powered up, but as soon as these messages cease, the receiving device would interpret this as an accidental disconnection. Commit f5f165418cab (ALSA: usb-audio: Fix missing autopm for MIDI input) introduced another regression: some devices (e.g. the Roland GAIA SH-01) are self-powered but do a reset whenever the USB interface's power state changes. To work around all this, just disable autopm for all USB MIDI devices. Reported-by: Laurens Holst Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- sound/usb/midi.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) -- 1.8.1.2