WSL2-Linux-Kernel/sound/pci/emu10k1
Maciej S. Szmigiero 04f8773a3e ALSA: emu10k1: add a IOMMU workaround
The Audigy 2 CA0102 chip (but most likely others from the emu10k1 family,
too) has a problem that from time to time it likes to do few DMA reads a
bit beyond its normal allocation and gets very confused if these reads get
blocked by a IOMMU.

For the first (reserved) page this happens multiple times at every
playback, for various synth pages it happens randomly, rarely for PCM
playback buffers and the page table memory itself.
All these reads seem to follow a similar pattern, observed read offsets
beyond the allocation end were 0x00, 0x40, 0x80 and 0xc0 (PCI cache line
multiples), so it looks like the device tries to accesses up to 256 extra
bytes.

As a workaround let's widen these DMA allocations by an extra page if we
detect that the device is behind a non-passthrough IOMMU (the DMA memory
should be relatively plenty on IOMMU systems).

Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-14 07:46:55 +01:00
..
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
emu10k1.c ALSA: seq: Allow the modular sequencer registration 2017-06-12 08:43:33 +02:00
emu10k1_callback.c ALSA: emu10k1: constify snd_emux_operators structure 2017-02-19 22:07:29 +01:00
emu10k1_main.c ALSA: emu10k1: add a IOMMU workaround 2018-02-14 07:46:55 +01:00
emu10k1_patch.c ALSA: emu10k1: Use standard printk helpers 2014-02-26 16:45:27 +01:00
emu10k1_synth.c ALSA: seq: Define driver object in each driver 2015-02-12 14:15:54 +01:00
emu10k1_synth_local.h [ALSA] Remove sound/driver.h 2008-01-31 17:29:48 +01:00
emu10k1x.c ALSA: emu10k1: make snd_pcm_hardware const 2017-08-12 23:31:45 +02:00
emufx.c ALSA: emu10k1: Fix forgotten user-copy conversion in init code 2017-08-18 10:59:02 +02:00
emumixer.c ALSA: pci: constify snd_kcontrol_new structures 2017-02-21 22:01:21 +01:00
emumpu401.c ALSA: pci: Constify snd_rawmidi_ops 2017-01-12 12:50:26 +01:00
emupcm.c ALSA: emu10k1: add a IOMMU workaround 2018-02-14 07:46:55 +01:00
emuproc.c ALSA: emu10k1: remove redundant assignment to tmp 2017-10-17 19:15:45 +02:00
io.c ALSA: emu10k1: Fix possible NULL dereference 2014-03-05 12:15:56 +01:00
irq.c ALSA: emu10k1: Use standard printk helpers 2014-02-26 16:45:27 +01:00
memory.c ALSA: emu10k1: add a IOMMU workaround 2018-02-14 07:46:55 +01:00
p16v.c ALSA: emu10k1: make snd_pcm_hardware const 2017-08-12 23:31:45 +02:00
p16v.h Fix common misspellings 2011-03-31 11:26:23 -03:00
p17v.h [ALSA] emu10k1: Add Audio capture support for Audigy 2 ZS Notebook. 2007-02-09 09:02:17 +01:00
timer.c ALSA: pci: remove __dev* attributes 2012-12-07 07:20:55 +01:00
tina2.h
voice.c ALSA: emu10k1: Use standard printk helpers 2014-02-26 16:45:27 +01:00