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path: root/include/sound/hda_regmap.h
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2016-04-21ALSA: hda - Fix possible race on regmap bypass flipTakashi Iwai1-0/+2
HD-audio driver uses regmap cache bypass feature for reading a raw value without the cache. But this is racy since both the cached and the uncached reads may occur concurrently. The former is done via the normal control API access while the latter comes from the proc file read. Even though the regmap itself has the protection against the concurrent accesses, the flag set/reset is done without the protection, so it may lead to inconsistent state of bypass flag that doesn't match with the current read and occasionally result in a kernel WARNING like: WARNING: CPU: 3 PID: 2731 at drivers/base/regmap/regcache.c:499 regcache_cache_only+0x78/0x93 One way to work around such a problem is to wrap with a mutex. But in this case, the solution is simpler: for the uncached read, we just skip the regmap and directly calls its accessor. The verb execution there is protected by itself, so basically it's safe to call individually. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=116171 Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-09-28ALSA: hda - Fix typos in snd_hdac_regmap_*() documentsTakashi Iwai1-2/+2
Fixes the wrong reference names to regmap amp functions. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-06-11ALSA: hda - Re-add the lost fake mute supportTakashi Iwai1-0/+2
Yet another regression by the transition to regmap cache; for better usability, we had the fake mute control using the zero amp value for Conexant codecs, and this was forgotten in the new hda core code. Since the bits 4-7 are unused for the amp registers (as we follow the syntax of AMP_GET verb), the bit 4 is now used to indicate the fake mute. For setting this flag, snd_hda_codec_amp_update() becomes a function from a simple macro. The bonus is that it gained a proper function description. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-04-04ALSA: hda - Sync node attributes at resume from widget power savingTakashi Iwai1-0/+12
So far we assumed that the node attributes like amp values remain during the power state transition of the node itself. While this is true for IDT/STAC codecs I've tested, but some other codecs don't seem behaving in that way. This patch implements a partial sync mechanism specific to the given widget node. Now we've merged the regmap support, and it can be easily written with regcache_sync_region(). Tested-by: Hui Wang <hui.wang@canonical.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-23ALSA: hda - Add a fake stereo amp register supportTakashi Iwai1-0/+59
HD-audio spec is inconvenient regarding the handling of stereo volume controls. It can set and get only single channel at once (although there is a special option to set the same value to both channels). This patch provides a fake pseudo-register via the regmap access so that the stereo channels can be read and written by a single call. It'd be useful, for example, for implementing DAPM widgets. A stereo amp pseudo register consists of the encoding like the normal amp verbs but it has both SET_LEFT (bit 13) and SET_RIGHT (bit 12) bits set. The regmap reads and writes a 16bit value for this pseudo register where the upper 8bit is for the right chanel and the lower 8bit for the left channel. Note that the driver doesn't recognize conflicts when both stereo and mono channel registers are mixed. Mixing them would certainly confuse the operation. So, use carefully. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-23ALSA: hda - Allow driver to add vendor-specific verbs for regmapTakashi Iwai1-1/+2
Codecs may have own vendor-specific verbs, and we need to allow each driver to give such verbs for cached accesses. Here a verb can be put into a single array and looked through it at readable and writeable callbacks. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2015-03-23ALSA: hda - Add regmap supportTakashi Iwai1-0/+145
This patch adds an infrastructure to support regmap-based verb accesses. Because o the asymmetric nature of HD-audio verbs, especially the amp verbs, we need to translate the verbs as a sort of pseudo registers to be mapped uniquely in regmap. In this patch, a pseudo register is built from the NID, the AC_VERB_GET_* and 8bit parameters, i.e. almost in the form to be sent to HD-audio bus but without codec address field. OTOH, for writing, the same pseudo register is translated to AC_VERB_SET_* automatically. The AC_VERB_SET_AMP_* verb is re-encoded from the corresponding AC_VERB_GET_AMP_* verb and parameter at writing. Some verbs has a single command for read but multiple for writes. A write for such a verb is split automatically to multiple verbs. The patch provides also a few handy helper functions. They are designed to be accessible even without regmap. When no regmap is set up (e.g. before the codec device instantiation), the direct hardware access is used. Also, it tries to avoid the unnecessary power-up. The power up/down sequence is performed only on demand. The codec driver needs to call snd_hdac_regmap_exit() and snd_hdac_regmap_exit() at probe and remove if it wants the regmap access. There is one flag added to hdac_device. When the flag lazy_cache is set, regmap helper ignores a write for a suspended device and returns as if it was actually written. It reduces the hardware access pretty much, e.g. when adjusting the mixer volume while in idle. This assumes that the driver will sync the cache later at resume properly, so use it carefully. Signed-off-by: Takashi Iwai <tiwai@suse.de>