1 files changed, 43 insertions, 2 deletions

diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 02ff0363d3ad..3a911cfb5ff3 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -1182,6 +1182,47 @@ static void context_tasklet(unsigned long data)
 	}
 }
 
+static void ohci_isoc_context_work(struct work_struct *work)
+{
+	struct fw_iso_context *base = container_of(work, struct fw_iso_context, work);
+	struct iso_context *isoc_ctx = container_of(base, struct iso_context, base);
+	struct context *ctx = &isoc_ctx->context;
+	struct descriptor *d, *last;
+	u32 address;
+	int z;
+	struct descriptor_buffer *desc;
+
+	desc = list_entry(ctx->buffer_list.next, struct descriptor_buffer, list);
+	last = ctx->last;
+	while (last->branch_address != 0) {
+		struct descriptor_buffer *old_desc = desc;
+
+		address = le32_to_cpu(last->branch_address);
+		z = address & 0xf;
+		address &= ~0xf;
+		ctx->current_bus = address;
+
+		// If the branch address points to a buffer outside of the current buffer, advance
+		// to the next buffer.
+		if (address < desc->buffer_bus || address >= desc->buffer_bus + desc->used)
+			desc = list_entry(desc->list.next, struct descriptor_buffer, list);
+		d = desc->buffer + (address - desc->buffer_bus) / sizeof(*d);
+		last = find_branch_descriptor(d, z);
+
+		if (!ctx->callback(ctx, d, last))
+			break;
+
+		if (old_desc != desc) {
+			// If we've advanced to the next buffer, move the previous buffer to the
+			// free list.
+			old_desc->used = 0;
+			guard(spinlock_irqsave)(&ctx->ohci->lock);
+			list_move_tail(&old_desc->list, &ctx->buffer_list);
+		}
+		ctx->last = last;
+	}
+}
+
 /*
  * Allocate a new buffer and add it to the list of free buffers for this
  * context.  Must be called with ohci->lock held.
@@ -3128,6 +3169,7 @@ static struct fw_iso_context *ohci_allocate_iso_context(struct fw_card *card,
 	ret = context_init(&ctx->context, ohci, regs, callback);
 	if (ret < 0)
 		goto out_with_header;
+	fw_iso_context_init_work(&ctx->base, ohci_isoc_context_work);
 
 	if (type == FW_ISO_CONTEXT_RECEIVE_MULTICHANNEL) {
 		set_multichannel_mask(ohci, 0);
@@ -3582,8 +3624,7 @@ static int ohci_flush_iso_completions(struct fw_iso_context *base)
 	int ret = 0;
 
 	if (!test_and_set_bit_lock(0, &ctx->flushing_completions)) {
-		// Note that tasklet softIRQ is not used to process isochronous context anymore.
-		context_tasklet((unsigned long)&ctx->context);
+		ohci_isoc_context_work(&base->work);
 
 		switch (base->type) {
 		case FW_ISO_CONTEXT_TRANSMIT: