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| author | Mark Brown <broonie@kernel.org> | 2018-06-01 11:40:46 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2018-06-01 11:40:46 +0100 |
| commit | 1e82572e5f806782cc1bf06e6d22905c28b0a9f5 (patch) | |
| tree | c428a640fca2ee5c6bfe259482b941f5e0ece927 /drivers/firewire/ohci.c | |
| parent | 29e8549d35499289ce6211a553f956a2ab9a3905 (diff) | |
| parent | 86a04ba0955e3c806ed301cf178f1e130f1cb785 (diff) | |
Merge branch 'linux-linaro-lsk-v4.9' into linux-linaro-lsk-v4.9-rtlsk-v4.9-18.05-rt
Diffstat (limited to 'drivers/firewire/ohci.c')
| -rw-r--r-- | drivers/firewire/ohci.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c index 8bf89267dc25..d731b413cb2c 100644 --- a/drivers/firewire/ohci.c +++ b/drivers/firewire/ohci.c @@ -1130,7 +1130,13 @@ static int context_add_buffer(struct context *ctx) return -ENOMEM; offset = (void *)&desc->buffer - (void *)desc; - desc->buffer_size = PAGE_SIZE - offset; + /* + * Some controllers, like JMicron ones, always issue 0x20-byte DMA reads + * for descriptors, even 0x10-byte ones. This can cause page faults when + * an IOMMU is in use and the oversized read crosses a page boundary. + * Work around this by always leaving at least 0x10 bytes of padding. + */ + desc->buffer_size = PAGE_SIZE - offset - 0x10; desc->buffer_bus = bus_addr + offset; desc->used = 0; |