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Commit 82b662dc authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Stefan Richter
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firewire: ohci: flush AT contexts after bus reset for OHCI 1.2 



The OHCI 1.2 (draft) specification, clause 7.2.3.3, allows and
recommends that, after a bus reset, the controller does not flush all
the packets in the AT queues.  Therefore, the driver has to do this
itself.

Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent c1671470

drivers/firewire/ohci.c

+39 −7
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ struct context { 
	struct fw_ohci *ohci;

	u32 regs;

	int total_allocation;

	bool flushing;



	/*

	 * List of page-sized buffers for storing DMA descriptors.
@@ -1356,6 +1357,17 @@ static int at_context_queue_packet(struct context *ctx, 
	return 0;

}



static void at_context_flush(struct context *ctx)

{

	tasklet_disable(&ctx->tasklet);



	ctx->flushing = true;

	context_tasklet((unsigned long)ctx);

	ctx->flushing = false;



	tasklet_enable(&ctx->tasklet);

}



static int handle_at_packet(struct context *context,

			    struct descriptor *d,

			    struct descriptor *last)
@@ -1365,7 +1377,7 @@ static int handle_at_packet(struct context *context, 
	struct fw_ohci *ohci = context->ohci;

	int evt;



	if (last->transfer_status == 0)

	if (last->transfer_status == 0 && !context->flushing)

		/* This descriptor isn't done yet, stop iteration. */

		return 0;
@@ -1399,11 +1411,15 @@ static int handle_at_packet(struct context *context, 
		break;



	case OHCI1394_evt_missing_ack:

		if (context->flushing)

			packet->ack = RCODE_GENERATION;

		else {

			/*

			 * Using a valid (current) generation count, but the

			 * node is not on the bus or not sending acks.

			 */

			packet->ack = RCODE_NO_ACK;

		}

		break;



	case ACK_COMPLETE + 0x10:
@@ -1416,6 +1432,13 @@ static int handle_at_packet(struct context *context, 
		packet->ack = evt - 0x10;

		break;



	case OHCI1394_evt_no_status:

		if (context->flushing) {

			packet->ack = RCODE_GENERATION;

			break;

		}

		/* fall through */



	default:

		packet->ack = RCODE_SEND_ERROR;

		break;
@@ -1721,9 +1744,18 @@ static void bus_reset_tasklet(unsigned long data) 
	/* FIXME: Document how the locking works. */

	spin_lock_irqsave(&ohci->lock, flags);



	ohci->generation = generation;

	ohci->generation = -1; /* prevent AT packet queueing */

	context_stop(&ohci->at_request_ctx);

	context_stop(&ohci->at_response_ctx);



	spin_unlock_irqrestore(&ohci->lock, flags);



	at_context_flush(&ohci->at_request_ctx);

	at_context_flush(&ohci->at_response_ctx);



	spin_lock_irqsave(&ohci->lock, flags);



	ohci->generation = generation;

	reg_write(ohci, OHCI1394_IntEventClear, OHCI1394_busReset);



	if (ohci->quirks & QUIRK_RESET_PACKET)