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-rw-r--r--drivers/firewire/fw-ohci.c73
1 files changed, 35 insertions, 38 deletions
diff --git a/drivers/firewire/fw-ohci.c b/drivers/firewire/fw-ohci.c
index 6d19828..bbfd6cd 100644
--- a/drivers/firewire/fw-ohci.c
+++ b/drivers/firewire/fw-ohci.c
@@ -1765,6 +1765,28 @@ ohci_get_bus_time(struct fw_card *card)
return bus_time;
}
+static void copy_iso_headers(struct iso_context *ctx, void *p)
+{
+ int i = ctx->header_length;
+
+ if (i + ctx->base.header_size > PAGE_SIZE)
+ return;
+
+ /*
+ * The iso header is byteswapped to little endian by
+ * the controller, but the remaining header quadlets
+ * are big endian. We want to present all the headers
+ * as big endian, so we have to swap the first quadlet.
+ */
+ if (ctx->base.header_size > 0)
+ *(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
+ if (ctx->base.header_size > 4)
+ *(u32 *) (ctx->header + i + 4) = __swab32(*(u32 *) p);
+ if (ctx->base.header_size > 8)
+ memcpy(ctx->header + i + 8, p + 8, ctx->base.header_size - 8);
+ ctx->header_length += ctx->base.header_size;
+}
+
static int handle_ir_dualbuffer_packet(struct context *context,
struct descriptor *d,
struct descriptor *last)
@@ -1775,7 +1797,6 @@ static int handle_ir_dualbuffer_packet(struct context *context,
__le32 *ir_header;
size_t header_length;
void *p, *end;
- int i;
if (db->first_res_count != 0 && db->second_res_count != 0) {
if (ctx->excess_bytes <= le16_to_cpu(db->second_req_count)) {
@@ -1788,25 +1809,14 @@ static int handle_ir_dualbuffer_packet(struct context *context,
header_length = le16_to_cpu(db->first_req_count) -
le16_to_cpu(db->first_res_count);
- i = ctx->header_length;
p = db + 1;
end = p + header_length;
- while (p < end && i + ctx->base.header_size <= PAGE_SIZE) {
- /*
- * The iso header is byteswapped to little endian by
- * the controller, but the remaining header quadlets
- * are big endian. We want to present all the headers
- * as big endian, so we have to swap the first
- * quadlet.
- */
- *(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
- memcpy(ctx->header + i + 4, p + 8, ctx->base.header_size - 4);
- i += ctx->base.header_size;
+ while (p < end) {
+ copy_iso_headers(ctx, p);
ctx->excess_bytes +=
(le32_to_cpu(*(__le32 *)(p + 4)) >> 16) & 0xffff;
- p += ctx->base.header_size + 4;
+ p += max(ctx->base.header_size, (size_t)8);
}
- ctx->header_length = i;
ctx->excess_bytes -= le16_to_cpu(db->second_req_count) -
le16_to_cpu(db->second_res_count);
@@ -1832,7 +1842,6 @@ static int handle_ir_packet_per_buffer(struct context *context,
struct descriptor *pd;
__le32 *ir_header;
void *p;
- int i;
for (pd = d; pd <= last; pd++) {
if (pd->transfer_status)
@@ -1842,21 +1851,8 @@ static int handle_ir_packet_per_buffer(struct context *context,
/* Descriptor(s) not done yet, stop iteration */
return 0;
- i = ctx->header_length;
- p = last + 1;
-
- if (ctx->base.header_size > 0 &&
- i + ctx->base.header_size <= PAGE_SIZE) {
- /*
- * The iso header is byteswapped to little endian by
- * the controller, but the remaining header quadlets
- * are big endian. We want to present all the headers
- * as big endian, so we have to swap the first quadlet.
- */
- *(u32 *) (ctx->header + i) = __swab32(*(u32 *) (p + 4));
- memcpy(ctx->header + i + 4, p + 8, ctx->base.header_size - 4);
- ctx->header_length += ctx->base.header_size;
- }
+ p = last + 1;
+ copy_iso_headers(ctx, p);
if (le16_to_cpu(last->control) & DESCRIPTOR_IRQ_ALWAYS) {
ir_header = (__le32 *) p;
@@ -2151,11 +2147,11 @@ ohci_queue_iso_receive_dualbuffer(struct fw_iso_context *base,
z = 2;
/*
- * The OHCI controller puts the status word in the header
- * buffer too, so we need 4 extra bytes per packet.
+ * The OHCI controller puts the isochronous header and trailer in the
+ * buffer, so we need at least 8 bytes.
*/
packet_count = p->header_length / ctx->base.header_size;
- header_size = packet_count * (ctx->base.header_size + 4);
+ header_size = packet_count * max(ctx->base.header_size, (size_t)8);
/* Get header size in number of descriptors. */
header_z = DIV_ROUND_UP(header_size, sizeof(*d));
@@ -2173,7 +2169,8 @@ ohci_queue_iso_receive_dualbuffer(struct fw_iso_context *base,
db = (struct db_descriptor *) d;
db->control = cpu_to_le16(DESCRIPTOR_STATUS |
DESCRIPTOR_BRANCH_ALWAYS);
- db->first_size = cpu_to_le16(ctx->base.header_size + 4);
+ db->first_size =
+ cpu_to_le16(max(ctx->base.header_size, (size_t)8));
if (p->skip && rest == p->payload_length) {
db->control |= cpu_to_le16(DESCRIPTOR_WAIT);
db->first_req_count = db->first_size;
@@ -2223,11 +2220,11 @@ ohci_queue_iso_receive_packet_per_buffer(struct fw_iso_context *base,
int page, offset, packet_count, header_size, payload_per_buffer;
/*
- * The OHCI controller puts the status word in the
- * buffer too, so we need 4 extra bytes per packet.
+ * The OHCI controller puts the isochronous header and trailer in the
+ * buffer, so we need at least 8 bytes.
*/
packet_count = p->header_length / ctx->base.header_size;
- header_size = ctx->base.header_size + 4;
+ header_size = max(ctx->base.header_size, (size_t)8);
/* Get header size in number of descriptors. */
header_z = DIV_ROUND_UP(header_size, sizeof(*d));
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