firewire: fw-sbp2: fix DMA mapping of S/G tables
- The CPU must not touch the buffer after it was DMA-mapped.
- The size argument of dma_unmap_single(...page_table...) was bogus.
- Move a comment closer to the code to which it refers to.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index c7518ea..a2ddf31 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -887,7 +887,7 @@
if (orb->page_table_bus != 0)
dma_unmap_single(device->card->device, orb->page_table_bus,
- sizeof(orb->page_table_bus), DMA_TO_DEVICE);
+ sizeof(orb->page_table), DMA_TO_DEVICE);
orb->cmd->result = result;
orb->done(orb->cmd);
@@ -902,7 +902,6 @@
struct fw_device *device = fw_device(unit->device.parent);
struct scatterlist *sg;
int sg_len, l, i, j, count;
- size_t size;
dma_addr_t sg_addr;
sg = (struct scatterlist *)orb->cmd->request_buffer;
@@ -951,7 +950,13 @@
}
}
- size = sizeof(orb->page_table[0]) * j;
+ fw_memcpy_to_be32(orb->page_table, orb->page_table,
+ sizeof(orb->page_table[0]) * j);
+ orb->page_table_bus =
+ dma_map_single(device->card->device, orb->page_table,
+ sizeof(orb->page_table), DMA_TO_DEVICE);
+ if (dma_mapping_error(orb->page_table_bus))
+ goto fail_page_table;
/*
* The data_descriptor pointer is the one case where we need
@@ -960,20 +965,12 @@
* initiator (i.e. us), but data_descriptor can refer to data
* on other nodes so we need to put our ID in descriptor.high.
*/
-
- orb->page_table_bus =
- dma_map_single(device->card->device, orb->page_table,
- size, DMA_TO_DEVICE);
- if (dma_mapping_error(orb->page_table_bus))
- goto fail_page_table;
orb->request.data_descriptor.high = sd->address_high;
orb->request.data_descriptor.low = orb->page_table_bus;
orb->request.misc |=
COMMAND_ORB_PAGE_TABLE_PRESENT |
COMMAND_ORB_DATA_SIZE(j);
- fw_memcpy_to_be32(orb->page_table, orb->page_table, size);
-
return 0;
fail_page_table: