linux_dsm_epyc7002/sound/pci/hda/hda_i915.h
Wang Xingchao 99a2008d0b ALSA: hda - Add power-welll support for haswell HDA
For Intel Haswell chip, HDA controller and codec have
power well dependency from GPU side. This patch added support
to request/release power well in audio driver. Power save
feature should be enabled to get runtime power saving.

There's deadlock when request_module(i915) in azx_probe.
It looks like:
device_lock(audio pci device) -> azx_probe -> module_request
(or symbol_request) -> modprobe (userspace) -> i915 init ->
drm_pci_init -> pci_register_driver -> bus_add_driver -> driver_attach ->
which in turn tries all locks on pci bus, and when it tries the one on the
audio device, it will deadlock.

This patch introduce a work to store remaining probe stuff, and let
request_module run in safe work context.

Signed-off-by: Wang Xingchao <xingchao.wang@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Liam Girdwood <liam.r.girdwood@intel.com>
Reviewed-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-06-06 17:31:56 +02:00

36 lines
1.1 KiB
C

/*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59
* Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifndef __SOUND_HDA_I915_H
#define __SOUND_HDA_I915_H
#ifdef CONFIG_SND_HDA_I915
void hda_display_power(bool enable);
int hda_i915_init(void);
int hda_i915_exit(void);
#else
static inline void hda_display_power(bool enable) {}
static inline int hda_i915_init(void)
{
return -ENODEV;
}
static inline int hda_i915_exit(void)
{
return 0;
}
#endif
#endif