firewire: ohci: 0 may be a valid DMA address
I was told that there are obscure architectures with non-coherent DMA
which may DMA-map to bus address 0. We shall not use 0 as a magic
number of uninitialized bus address variables.
The packet->payload_length > 0 test cannot be used either (except in
at_context_queue_packet) because local requests are not DMA-mapped
regardless of payload_length. Hence add a state flag to struct
fw_packet.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 66789c3..842739d 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -226,7 +226,7 @@
packet->speed = speed;
packet->generation = generation;
packet->ack = 0;
- packet->payload_bus = 0;
+ packet->payload_mapped = false;
}
/**
@@ -601,7 +601,7 @@
WARN(1, KERN_ERR "wrong tcode %d", tcode);
}
- response->payload_bus = 0;
+ response->payload_mapped = false;
}
EXPORT_SYMBOL(fw_fill_response);