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authorStefan Richter <stefanr@s5r6.in-berlin.de>2009-10-14 20:40:10 +0200
committerStefan Richter <stefanr@s5r6.in-berlin.de>2009-10-31 11:40:51 +0100
commit19593ffdb6daa6ba691d247a2400cece12687c52 (patch)
tree18c3508bbdb5f2d1b1bf51ac653ec580043a9340 /drivers/firewire
parentfirewire: core: WARN on wrong usage of core transaction functions (diff)
downloadlinux-19593ffdb6daa6ba691d247a2400cece12687c52.tar.xz
linux-19593ffdb6daa6ba691d247a2400cece12687c52.zip
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>
Diffstat (limited to 'drivers/firewire')
-rw-r--r--drivers/firewire/core-transaction.c4
-rw-r--r--drivers/firewire/ohci.c9
2 files changed, 7 insertions, 6 deletions
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index 66789c3cc561..842739df23e2 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -226,7 +226,7 @@ static void fw_fill_request(struct fw_packet *packet, int tcode, int tlabel,
packet->speed = speed;
packet->generation = generation;
packet->ack = 0;
- packet->payload_bus = 0;
+ packet->payload_mapped = false;
}
/**
@@ -601,7 +601,7 @@ void fw_fill_response(struct fw_packet *response, u32 *request_header,
WARN(1, KERN_ERR "wrong tcode %d", tcode);
}
- response->payload_bus = 0;
+ response->payload_mapped = false;
}
EXPORT_SYMBOL(fw_fill_response);
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 418415564791..a71477541dc7 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -995,7 +995,8 @@ static int at_context_queue_packet(struct context *ctx,
packet->ack = RCODE_SEND_ERROR;
return -1;
}
- packet->payload_bus = payload_bus;
+ packet->payload_bus = payload_bus;
+ packet->payload_mapped = true;
d[2].req_count = cpu_to_le16(packet->payload_length);
d[2].data_address = cpu_to_le32(payload_bus);
@@ -1023,7 +1024,7 @@ static int at_context_queue_packet(struct context *ctx,
*/
if (ohci->generation != packet->generation ||
reg_read(ohci, OHCI1394_IntEventSet) & OHCI1394_busReset) {
- if (packet->payload_length > 0)
+ if (packet->payload_mapped)
dma_unmap_single(ohci->card.device, payload_bus,
packet->payload_length, DMA_TO_DEVICE);
packet->ack = RCODE_GENERATION;
@@ -1059,7 +1060,7 @@ static int handle_at_packet(struct context *context,
/* This packet was cancelled, just continue. */
return 1;
- if (packet->payload_bus)
+ if (packet->payload_mapped)
dma_unmap_single(ohci->card.device, packet->payload_bus,
packet->payload_length, DMA_TO_DEVICE);
@@ -1723,7 +1724,7 @@ static int ohci_cancel_packet(struct fw_card *card, struct fw_packet *packet)
if (packet->ack != 0)
goto out;
- if (packet->payload_bus)
+ if (packet->payload_mapped)
dma_unmap_single(ohci->card.device, packet->payload_bus,
packet->payload_length, DMA_TO_DEVICE);