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Commit 19593ffd authored by Stefan Richter's avatar Stefan Richter
Browse files

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: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 5b189bf3

drivers/firewire/core-transaction.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

drivers/firewire/ohci.c

+5 −4
Original line number Diff line number Diff line
@@ -996,6 +996,7 @@ static int at_context_queue_packet(struct context *ctx, 
			return -1;

		}

		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);

include/linux/firewire.h

+1 −0
Original line number Diff line number Diff line
@@ -267,6 +267,7 @@ struct fw_packet { 
	void *payload;

	size_t payload_length;

	dma_addr_t payload_bus;

	bool payload_mapped;

	u32 timestamp;



	/*