linux/sound/hda
Takashi Iwai c31427d0d2 ALSA: hda: No preallocation on x86 platforms
Like many other drivers, HD-audio drivers also do PCM buffer
preallocation to assure the buffer pages allocated at the early boot
stage.  This step is useful for platforms that may fail to allocate
the PCM hardware buffers -- which is mostly for either large
continuous pages or with the specific DMA mask (like emu10k1).

OTOH, when a buffer is allocated as SG-buffer and the DMA mask is
either 32 or 64 bits, the allocation almost never fails unless it hits
the real OOM situation.  In such a case, we don't need the
preallocation inevitably unlike the cases above.

That said, we may drop the preallocation for HD-audio that does
allocate via SG-buffers, and the patch achieves it.

However, there is one caveat: the buffer allocation behavior depends
on CONFIG_SND_DMA_SGBUF, and it falls back to the continuous pages
when it's not set.  And, currently this SG buffer allocation is
enabled only on x86 platforms.  So, covering those fall-outs, the
patch adjusts CONFIG_SND_HDA_PREALLOC_SIZE depending on the condition,
and keeps the old behavior as-is for non-x86 platforms.

On x86, the kconfig item is no longer adjustable but always set to
zero for disabling the preallocation.  You can still enable the
preallocation via procfs interface at any time later, too.

Link: https://lore.kernel.org/r/20200120124423.11862-2-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-21 07:12:08 +01:00
..
ext ALSA: hda: Update kernel-doc function parameter descriptions 2020-01-14 07:40:37 +01:00
Kconfig ALSA: hda: No preallocation on x86 platforms 2020-01-21 07:12:08 +01:00
Makefile ALSA: hda: add Intel DSP configuration / probe code 2019-10-23 06:31:37 +02:00
array.c treewide: Add SPDX license identifier for missed files 2019-05-21 10:50:45 +02:00
hda_bus_type.c treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
hdac_bus.c ALSA: hda: Update kernel-doc function parameter descriptions 2020-01-14 07:40:37 +01:00
hdac_component.c ALSA: hda: Update kernel-doc function parameter descriptions 2020-01-14 07:40:37 +01:00
hdac_controller.c ALSA: hda: Update kernel-doc function parameter descriptions 2020-01-14 07:40:37 +01:00
hdac_device.c ALSA: hda: Update kernel-doc function parameter descriptions 2020-01-14 07:40:37 +01:00
hdac_i915.c ALSA: hda: Fix 1-minute detection delay when i915 module is not available 2019-07-27 08:31:46 +02:00
hdac_regmap.c ALSA: hda: Manage concurrent reg access more properly 2020-01-13 13:40:41 +01:00
hdac_stream.c ALSA: hda: Update kernel-doc function parameter descriptions 2020-01-14 07:40:37 +01:00
hdac_sysfs.c ALSA: hda: Simplify snd_hdac_refresh_widgets() 2019-07-05 12:01:06 +02:00
hdmi_chmap.c ALSA: hda: More constifications 2020-01-05 16:14:32 +01:00
intel-dsp-config.c ALSA: hda: Allow non-Intel device probe gracefully 2019-10-28 16:09:02 +01:00
intel-nhlt.c ALSA: hda: More constifications 2020-01-05 16:14:32 +01:00
local.h ALSA: hda: Unexport a few more stuff 2019-08-14 20:00:56 +02:00
trace.c ALSA: hda - Re-add tracepoints to HD-audio core driver 2015-03-23 13:17:58 +01:00
trace.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00