99a2008d0b
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>
75 lines
1.8 KiB
C
75 lines
1.8 KiB
C
/*
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* hda_i915.c - routines for Haswell HDA controller power well support
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <linux/init.h>
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#include <linux/module.h>
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#include <sound/core.h>
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#include <drm/i915_powerwell.h>
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#include "hda_i915.h"
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static void (*get_power)(void);
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static void (*put_power)(void);
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void hda_display_power(bool enable)
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{
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if (!get_power || !put_power)
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return;
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snd_printdd("HDA display power %s \n",
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enable ? "Enable" : "Disable");
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if (enable)
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get_power();
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else
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put_power();
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}
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int hda_i915_init(void)
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{
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int err = 0;
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get_power = symbol_request(i915_request_power_well);
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if (!get_power) {
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snd_printk(KERN_WARNING "hda-i915: get_power symbol get fail\n");
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return -ENODEV;
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}
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put_power = symbol_request(i915_release_power_well);
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if (!put_power) {
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symbol_put(i915_request_power_well);
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get_power = NULL;
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return -ENODEV;
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}
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snd_printd("HDA driver get symbol successfully from i915 module\n");
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return err;
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}
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int hda_i915_exit(void)
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{
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if (get_power) {
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symbol_put(i915_request_power_well);
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get_power = NULL;
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}
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if (put_power) {
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symbol_put(i915_release_power_well);
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put_power = NULL;
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}
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return 0;
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}
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