/* * Power management for audio on multifunction CS5535 companion device * Copyright (C) Jaya Kumar * * 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 * */ #include #include #include #include #include #include #include #include #include #include "cs5535audio.h" static void snd_cs5535audio_stop_hardware(struct cs5535audio *cs5535au) { /* we depend on snd_ac97_suspend to tell the AC97 codec to shutdown. the amd spec suggests that the LNK_SHUTDOWN be done at the same time that the codec power-down is issued. instead, we do it just after rather than at the same time. excluding codec specific build_ops->suspend ac97 powerdown hits: 0x8000 EAPD 0x4000 Headphone amplifier 0x0300 ADC & DAC 0x0400 Analog Mixer powerdown (Vref on) I am not sure if this is the best that we can do. The remainder to be investigated are: - analog mixer (vref off) 0x0800 - AC-link powerdown 0x1000 - codec internal clock 0x2000 */ /* set LNK_SHUTDOWN to shutdown AC link */ cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_SHUTDOWN); } static int snd_cs5535audio_suspend(struct device *dev) { struct snd_card *card = dev_get_drvdata(dev); struct cs5535audio *cs5535au = card->private_data; int i; snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); snd_pcm_suspend_all(cs5535au->pcm); snd_ac97_suspend(cs5535au->ac97); for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) { struct cs5535audio_dma *dma = &cs5535au->dmas[i]; if (dma && dma->substream) dma->saved_prd = dma->ops->read_prd(cs5535au); } /* save important regs, then disable aclink in hw */ snd_cs5535audio_stop_hardware(cs5535au); return 0; } static int snd_cs5535audio_resume(struct device *dev) { struct snd_card *card = dev_get_drvdata(dev); struct cs5535audio *cs5535au = card->private_data; u32 tmp; int timeout; int i; /* set LNK_WRM_RST to reset AC link */ cs_writel(cs5535au, ACC_CODEC_CNTL, ACC_CODEC_CNTL_LNK_WRM_RST); timeout = 50; do { tmp = cs_readl(cs5535au, ACC_CODEC_STATUS); if (tmp & PRM_RDY_STS) break; udelay(1); } while (--timeout); if (!timeout) dev_err(cs5535au->card->dev, "Failure getting AC Link ready\n"); /* set up rate regs, dma. actual initiation is done in trig */ for (i = 0; i < NUM_CS5535AUDIO_DMAS; i++) { struct cs5535audio_dma *dma = &cs5535au->dmas[i]; if (dma && dma->substream) { dma->substream->ops->prepare(dma->substream); dma->ops->setup_prd(cs5535au, dma->saved_prd); } } /* we depend on ac97 to perform the codec power up */ snd_ac97_resume(cs5535au->ac97); snd_power_change_state(card, SNDRV_CTL_POWER_D0); return 0; } SIMPLE_DEV_PM_OPS(snd_cs5535audio_pm, snd_cs5535audio_suspend, snd_cs5535audio_resume); t name='context' onchange='this.form.submit();'>space:mode:
authorDouglas Miller <dougmill@linux.vnet.ibm.com>2017-01-28 06:42:20 -0600
committerTejun Heo <tj@kernel.org>2017-01-28 07:49:42 -0500
commit966d2b04e070bc040319aaebfec09e0144dc3341 (patch)
tree4b96156e3d1dd4dfd6039b7c219c9dc4616da52d /tools/perf/util/cs-etm.h
parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'tools/perf/util/cs-etm.h')