Commit 8c0c0cc2 authored by Jay Fenlason's avatar Jay Fenlason Committed by Stefan Richter
Browse files

firewire: ohci: handle receive packets with a data length of zero 



Queueing to receive an ISO packet with a payload length of zero
silently does nothing in dualbuffer mode, and crashes the kernel in
packet-per-buffer mode.  Return an error in dualbuffer mode, because
the DMA controller won't let us do what we want, and work correctly in
packet-per-buffer mode.

Signed-off-by: default avatarJay Fenlason <fenlason@redhat.com>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
Cc: stable@kernel.org
parent af0940da

drivers/firewire/ohci.c

+10 −2
Original line number Diff line number Diff line
@@ -2189,6 +2189,13 @@ static int ohci_queue_iso_receive_dualbuffer(struct fw_iso_context *base, 
	page     = payload >> PAGE_SHIFT;

	offset   = payload & ~PAGE_MASK;

	rest     = p->payload_length;

	/*

	 * The controllers I've tested have not worked correctly when

	 * second_req_count is zero.  Rather than do something we know won't

	 * work, return an error

	 */

	if (rest == 0)

		return -EINVAL;



	/* FIXME: make packet-per-buffer/dual-buffer a context option */

	while (rest > 0) {
@@ -2242,7 +2249,7 @@ static int ohci_queue_iso_receive_packet_per_buffer(struct fw_iso_context *base, 
					unsigned long payload)

{

	struct iso_context *ctx = container_of(base, struct iso_context, base);

	struct descriptor *d = NULL, *pd = NULL;

	struct descriptor *d, *pd;

	struct fw_iso_packet *p = packet;

	dma_addr_t d_bus, page_bus;

	u32 z, header_z, rest;
@@ -2280,8 +2287,9 @@ static int ohci_queue_iso_receive_packet_per_buffer(struct fw_iso_context *base, 
		d->data_address = cpu_to_le32(d_bus + (z * sizeof(*d)));



		rest = payload_per_buffer;

		pd = d;

		for (j = 1; j < z; j++) {

			pd = d + j;

			pd++;

			pd->control = cpu_to_le16(DESCRIPTOR_STATUS |

						  DESCRIPTOR_INPUT_MORE);

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