/*
 * ADAU7002 Stereo PDM-to-I2S/TDM converter driver
 *
 * Copyright 2014-2016 Analog Devices
 *  Author: Lars-Peter Clausen <lars@metafoo.de>
 *
 * Licensed under the GPL-2.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>

#include <sound/soc.h>

static const struct snd_soc_dapm_widget adau7002_widgets[] = {
	SND_SOC_DAPM_INPUT("PDM_DAT"),
	SND_SOC_DAPM_REGULATOR_SUPPLY("IOVDD", 0, 0),
};

static const struct snd_soc_dapm_route adau7002_routes[] = {
	{ "Capture", NULL, "PDM_DAT" },
	{ "Capture", NULL, "IOVDD" },
};

static struct snd_soc_dai_driver adau7002_dai = {
	.name = "adau7002-hifi",
	.capture = {
		.stream_name = "Capture",
		.channels_min = 2,
		.channels_max = 2,
		.rates = SNDRV_PCM_RATE_8000_96000,
		.formats = SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S18_3LE |
			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S24_LE |
			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S32_LE,
		.sig_bits = 20,
	},
};

static const struct snd_soc_codec_driver adau7002_codec_driver = {
	.component_driver = {
		.dapm_widgets		= adau7002_widgets,
		.num_dapm_widgets	= ARRAY_SIZE(adau7002_widgets),
		.dapm_routes		= adau7002_routes,
		.num_dapm_routes	= ARRAY_SIZE(adau7002_routes),
	},
};

static int adau7002_probe(struct platform_device *pdev)
{
	return snd_soc_register_codec(&pdev->dev, &adau7002_codec_driver,
			&adau7002_dai, 1);
}

static int adau7002_remove(struct platform_device *pdev)
{
	snd_soc_unregister_codec(&pdev->dev);
	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id adau7002_dt_ids[] = {
	{ .compatible = "adi,adau7002", },
	{ }
};
MODULE_DEVICE_TABLE(of, adau7002_dt_ids);
#endif

static struct platform_driver adau7002_driver = {
	.driver = {
		.name = "adau7002",
		.of_match_table	= of_match_ptr(adau7002_dt_ids),
	},
	.probe = adau7002_probe,
	.remove = adau7002_remove,
};
module_platform_driver(adau7002_driver);

MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("ADAU7002 Stereo PDM-to-I2S/TDM Converter driver");
MODULE_LICENSE("GPL v2");
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/fs?id=966d2b04e070bc040319aaebfec09e0144dc3341'>fs</a>/<a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs?id=966d2b04e070bc040319aaebfec09e0144dc3341'>xfs</a>/<a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_acl.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>xfs_acl.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='966d2b04e070bc040319aaebfec09e0144dc3341'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Douglas Miller &lt;dougmill@linux.vnet.ibm.com&gt;</td><td class='right'>2017-01-28 06:42:20 -0600</td></tr>
<tr><th>committer</th><td>Tejun Heo &lt;tj@kernel.org&gt;</td><td class='right'>2017-01-28 07:49:42 -0500</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_acl.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>966d2b04e070bc040319aaebfec09e0144dc3341</a> (<a href='/cgit.cgi/linux/net-next.git/patch/fs/xfs/xfs_acl.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>4b96156e3d1dd4dfd6039b7c219c9dc4616da52d</a> /<a href='/cgit.cgi/linux/net-next.git/tree/fs/xfs/xfs_acl.h?id=966d2b04e070bc040319aaebfec09e0144dc3341'>fs/xfs/xfs_acl.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/fs/xfs/xfs_acl.h?id=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>1b1bc42c1692e9b62756323c675a44cb1a1f9dbd</a> (<a href='/cgit.cgi/linux/net-next.git/diff/fs/xfs/xfs_acl.h?id=966d2b04e070bc040319aaebfec09e0144dc3341&amp;id2=1b1bc42c1692e9b62756323c675a44cb1a1f9dbd'>diff</a>)</td></tr></table>
<div class='commit-subject'>percpu-refcount: fix reference leak during percpu-atomic transition</div><div class='commit-msg'>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 &lt;dougmill@linux.vnet.ibm.com&gt;
Reviewed-by: Jens Axboe &lt;axboe@fb.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints")
Cc: stable@vger.kernel.org # v3.18+
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=966d2b04e070bc040319aaebfec09e0144dc3341'>Diffstat</a> (limited to 'fs/xfs/xfs_acl.h')</div><table summary='diffstat' class='diffstat'>