linux/include/sound/hda_regmap.h
Takashi Iwai 1a462be52f ALSA: hda: Manage concurrent reg access more properly
In the commit 8e85def572 ("ALSA: hda: enable regmap internal
locking"), we re-enabled the regmap lock due to the reported
regression that showed the possible concurrent accesses.  It was a
temporary workaround, and there are still a few opened races even
after the revert.  In this patch, we cover those still opened windows
with a proper mutex lock and disable the regmap internal lock again.

First off, the patch introduces a new snd_hdac_device.regmap_lock
mutex that is applied for each snd_hdac_regmap_*() call, including
read, write and update helpers.  The mutex is applied carefully so
that it won't block the self-power-up procedure in the helper
function.  Also, this assures the protection for the accesses without
regmap, too.

The snd_hdac_regmap_update_raw() is refactored to use the standard
regmap_update_bits_check() function instead of the open-code.  The
non-regmap case is still open-coded but it's an easy part.  The all
read and write operations are in the single mutex protection, so it's
now race-free.

In addition, a couple of new helper functions are added:
snd_hdac_regmap_update_raw_once() and snd_hdac_regmap_sync().  Both
are called from HD-audio legacy driver.  The former is to initialize
the given verb bits but only once when it's not initialized yet.  Due
to this condition, the function invokes regcache_cache_only(), and
it's now performed inside the regmap_lock (formerly it was racy) too.
The latter function is for simply invoking regcache_sync() inside the
regmap_lock, which is called from the codec resume call path.
Along with that, the HD-audio codec driver code is slightly modified /
simplified to adapt those new functions.

And finally, snd_hdac_regmap_read_raw(), *_write_raw(), etc are
rewritten with the helper macro.  It's just for simplification because
the code logic is identical among all those functions.

Tested-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Link: https://lore.kernel.org/r/20200109090104.26073-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-13 13:40:41 +01:00

225 lines
6.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* HD-audio regmap helpers
*/
#ifndef __SOUND_HDA_REGMAP_H
#define __SOUND_HDA_REGMAP_H
#include <linux/regmap.h>
#include <sound/core.h>
#include <sound/hdaudio.h>
#define AC_AMP_FAKE_MUTE 0x10 /* fake mute bit set to amp verbs */
int snd_hdac_regmap_init(struct hdac_device *codec);
void snd_hdac_regmap_exit(struct hdac_device *codec);
int snd_hdac_regmap_add_vendor_verb(struct hdac_device *codec,
unsigned int verb);
int snd_hdac_regmap_read_raw(struct hdac_device *codec, unsigned int reg,
unsigned int *val);
int snd_hdac_regmap_read_raw_uncached(struct hdac_device *codec,
unsigned int reg, unsigned int *val);
int snd_hdac_regmap_write_raw(struct hdac_device *codec, unsigned int reg,
unsigned int val);
int snd_hdac_regmap_update_raw(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val);
int snd_hdac_regmap_update_raw_once(struct hdac_device *codec, unsigned int reg,
unsigned int mask, unsigned int val);
void snd_hdac_regmap_sync(struct hdac_device *codec);
/**
* snd_hdac_regmap_encode_verb - encode the verb to a pseudo register
* @nid: widget NID
* @verb: codec verb
*
* Returns an encoded pseudo register.
*/
#define snd_hdac_regmap_encode_verb(nid, verb) \
(((verb) << 8) | 0x80000 | ((unsigned int)(nid) << 20))
/**
* snd_hdac_regmap_encode_amp - encode the AMP verb to a pseudo register
* @nid: widget NID
* @ch: channel (left = 0, right = 1)
* @dir: direction (#HDA_INPUT, #HDA_OUTPUT)
* @idx: input index value
*
* Returns an encoded pseudo register.
*/
#define snd_hdac_regmap_encode_amp(nid, ch, dir, idx) \
(snd_hdac_regmap_encode_verb(nid, AC_VERB_GET_AMP_GAIN_MUTE) | \
((ch) ? AC_AMP_GET_RIGHT : AC_AMP_GET_LEFT) | \
((dir) == HDA_OUTPUT ? AC_AMP_GET_OUTPUT : AC_AMP_GET_INPUT) | \
(idx))
/**
* snd_hdac_regmap_encode_amp_stereo - encode a pseudo register for stereo AMPs
* @nid: widget NID
* @dir: direction (#HDA_INPUT, #HDA_OUTPUT)
* @idx: input index value
*
* Returns an encoded pseudo register.
*/
#define snd_hdac_regmap_encode_amp_stereo(nid, dir, idx) \
(snd_hdac_regmap_encode_verb(nid, AC_VERB_GET_AMP_GAIN_MUTE) | \
AC_AMP_SET_LEFT | AC_AMP_SET_RIGHT | /* both bits set! */ \
((dir) == HDA_OUTPUT ? AC_AMP_GET_OUTPUT : AC_AMP_GET_INPUT) | \
(idx))
/**
* snd_hdac_regmap_write - Write a verb with caching
* @nid: codec NID
* @reg: verb to write
* @val: value to write
*
* For writing an amp value, use snd_hdac_regmap_update_amp().
*/
static inline int
snd_hdac_regmap_write(struct hdac_device *codec, hda_nid_t nid,
unsigned int verb, unsigned int val)
{
unsigned int cmd = snd_hdac_regmap_encode_verb(nid, verb);
return snd_hdac_regmap_write_raw(codec, cmd, val);
}
/**
* snd_hda_regmap_update - Update a verb value with caching
* @nid: codec NID
* @verb: verb to update
* @mask: bit mask to update
* @val: value to update
*
* For updating an amp value, use snd_hdac_regmap_update_amp().
*/
static inline int
snd_hdac_regmap_update(struct hdac_device *codec, hda_nid_t nid,
unsigned int verb, unsigned int mask,
unsigned int val)
{
unsigned int cmd = snd_hdac_regmap_encode_verb(nid, verb);
return snd_hdac_regmap_update_raw(codec, cmd, mask, val);
}
/**
* snd_hda_regmap_read - Read a verb with caching
* @nid: codec NID
* @verb: verb to read
* @val: pointer to store the value
*
* For reading an amp value, use snd_hda_regmap_get_amp().
*/
static inline int
snd_hdac_regmap_read(struct hdac_device *codec, hda_nid_t nid,
unsigned int verb, unsigned int *val)
{
unsigned int cmd = snd_hdac_regmap_encode_verb(nid, verb);
return snd_hdac_regmap_read_raw(codec, cmd, val);
}
/**
* snd_hdac_regmap_get_amp - Read AMP value
* @codec: HD-audio codec
* @nid: NID to read the AMP value
* @ch: channel (left=0 or right=1)
* @direction: #HDA_INPUT or #HDA_OUTPUT
* @index: the index value (only for input direction)
* @val: the pointer to store the value
*
* Read AMP value. The volume is between 0 to 0x7f, 0x80 = mute bit.
* Returns the value or a negative error.
*/
static inline int
snd_hdac_regmap_get_amp(struct hdac_device *codec, hda_nid_t nid,
int ch, int dir, int idx)
{
unsigned int cmd = snd_hdac_regmap_encode_amp(nid, ch, dir, idx);
int err, val;
err = snd_hdac_regmap_read_raw(codec, cmd, &val);
return err < 0 ? err : val;
}
/**
* snd_hdac_regmap_update_amp - update the AMP value
* @codec: HD-audio codec
* @nid: NID to read the AMP value
* @ch: channel (left=0 or right=1)
* @direction: #HDA_INPUT or #HDA_OUTPUT
* @idx: the index value (only for input direction)
* @mask: bit mask to set
* @val: the bits value to set
*
* Update the AMP value with a bit mask.
* Returns 0 if the value is unchanged, 1 if changed, or a negative error.
*/
static inline int
snd_hdac_regmap_update_amp(struct hdac_device *codec, hda_nid_t nid,
int ch, int dir, int idx, int mask, int val)
{
unsigned int cmd = snd_hdac_regmap_encode_amp(nid, ch, dir, idx);
return snd_hdac_regmap_update_raw(codec, cmd, mask, val);
}
/**
* snd_hdac_regmap_get_amp_stereo - Read stereo AMP values
* @codec: HD-audio codec
* @nid: NID to read the AMP value
* @ch: channel (left=0 or right=1)
* @direction: #HDA_INPUT or #HDA_OUTPUT
* @index: the index value (only for input direction)
* @val: the pointer to store the value
*
* Read stereo AMP values. The lower byte is left, the upper byte is right.
* Returns the value or a negative error.
*/
static inline int
snd_hdac_regmap_get_amp_stereo(struct hdac_device *codec, hda_nid_t nid,
int dir, int idx)
{
unsigned int cmd = snd_hdac_regmap_encode_amp_stereo(nid, dir, idx);
int err, val;
err = snd_hdac_regmap_read_raw(codec, cmd, &val);
return err < 0 ? err : val;
}
/**
* snd_hdac_regmap_update_amp_stereo - update the stereo AMP value
* @codec: HD-audio codec
* @nid: NID to read the AMP value
* @direction: #HDA_INPUT or #HDA_OUTPUT
* @idx: the index value (only for input direction)
* @mask: bit mask to set
* @val: the bits value to set
*
* Update the stereo AMP value with a bit mask.
* The lower byte is left, the upper byte is right.
* Returns 0 if the value is unchanged, 1 if changed, or a negative error.
*/
static inline int
snd_hdac_regmap_update_amp_stereo(struct hdac_device *codec, hda_nid_t nid,
int dir, int idx, int mask, int val)
{
unsigned int cmd = snd_hdac_regmap_encode_amp_stereo(nid, dir, idx);
return snd_hdac_regmap_update_raw(codec, cmd, mask, val);
}
/**
* snd_hdac_regmap_sync_node - sync the widget node attributes
* @codec: HD-audio codec
* @nid: NID to sync
*/
static inline void
snd_hdac_regmap_sync_node(struct hdac_device *codec, hda_nid_t nid)
{
regcache_mark_dirty(codec->regmap);
regcache_sync_region(codec->regmap, nid << 20, ((nid + 1) << 20) - 1);
}
#endif /* __SOUND_HDA_REGMAP_H */