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| author | Maciej S. Szmigiero <mail@maciej.szmigiero.name> | 2018-02-14 00:07:58 +0100 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-02-14 07:46:55 +0100 |
| commit | 04f8773a3e980f60953e7aeb36ec6c2631e11f10 (patch) | |
| tree | d6acfcbfd79924f50f46886683ca6c5f391d0b4f /include/sound | |
| parent | 055e0ae10f509482ca5b140e8e5f4a77e31efdd5 (diff) | |
| download | linux-04f8773a3e980f60953e7aeb36ec6c2631e11f10.tar.bz2 | |
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>
Diffstat (limited to 'include/sound')
| -rw-r--r-- | include/sound/emu10k1.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/sound/emu10k1.h b/include/sound/emu10k1.h index db32b7de52e0..5ebcc51c0a6a 100644 --- a/include/sound/emu10k1.h +++ b/include/sound/emu10k1.h @@ -1710,6 +1710,7 @@ struct snd_emu10k1 { unsigned int ecard_ctrl; /* ecard control bits */ unsigned int address_mode; /* address mode */ unsigned long dma_mask; /* PCI DMA mask */ + bool iommu_workaround; /* IOMMU workaround needed */ unsigned int delay_pcm_irq; /* in samples */ int max_cache_pages; /* max memory size / PAGE_SIZE */ struct snd_dma_buffer silent_page; /* silent page */ @@ -1877,6 +1878,8 @@ void snd_p16v_resume(struct snd_emu10k1 *emu); /* memory allocation */ struct snd_util_memblk *snd_emu10k1_alloc_pages(struct snd_emu10k1 *emu, struct snd_pcm_substream *substream); int snd_emu10k1_free_pages(struct snd_emu10k1 *emu, struct snd_util_memblk *blk); +int snd_emu10k1_alloc_pages_maybe_wider(struct snd_emu10k1 *emu, size_t size, + struct snd_dma_buffer *dmab); struct snd_util_memblk *snd_emu10k1_synth_alloc(struct snd_emu10k1 *emu, unsigned int size); int snd_emu10k1_synth_free(struct snd_emu10k1 *emu, struct snd_util_memblk *blk); int snd_emu10k1_synth_bzero(struct snd_emu10k1 *emu, struct snd_util_memblk *blk, int offset, int size); |