[PATCH] firewire: core: abort pending transactions at card removal

[Takashi S. <o-t...@sa...>]

IEEE 1394 defines the split, concatenated, and unified transaction.
To support the split transaction, core function uses linked list to
maintain the transactions waiting for acknowledge packet. After clearing
sources of hardware interrupts, the acknowledge packet is no longer
handled, therefore it is required to abort the pending transactions.

This commit executes callback with RCODE_CANCELLED for the pending
transactions at card removal.

Signed-off-by: Takashi Sakamoto <o-t...@sa...>
---
 drivers/firewire/core-card.c        |  1 +
 drivers/firewire/core-transaction.c | 28 ++++++++++++++++++++++++++++
 drivers/firewire/core.h             |  2 ++
 drivers/firewire/ohci.c             |  5 -----
 4 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/drivers/firewire/core-card.c b/drivers/firewire/core-card.c
index 65bd9db996c0..9869ea3fd9fc 100644
--- a/drivers/firewire/core-card.c
+++ b/drivers/firewire/core-card.c
@@ -790,6 +790,7 @@ void fw_core_remove_card(struct fw_card *card)
 	drain_workqueue(card->isoc_wq);
 	drain_workqueue(card->async_wq);
 	card->driver->disable(card);
+	fw_cancel_pending_transactions(card);
 
 	scoped_guard(spinlock_irqsave, &card->lock)
 		fw_destroy_nodes(card);
diff --git a/drivers/firewire/core-transaction.c b/drivers/firewire/core-transaction.c
index e80791d6d46b..fe96429ba395 100644
--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -51,6 +51,34 @@ static void remove_transaction_entry(struct fw_card *card, struct fw_transaction
 	card->transactions.tlabel_mask &= ~(1ULL << entry->tlabel);
 }
 
+// Must be called without holding card->transactions.lock.
+void fw_cancel_pending_transactions(struct fw_card *card)
+{
+	struct fw_transaction *t, *tmp;
+	LIST_HEAD(pending_list);
+
+	// NOTE: This can be without irqsave when we can guarantee that __fw_send_request() for
+	// local destination never runs in any type of IRQ context.
+	scoped_guard(spinlock_irqsave, &card->transactions.lock) {
+		list_for_each_entry_safe(t, tmp, &card->transactions.list, link) {
+			if (try_cancel_split_timeout(t))
+				list_move(&t->link, &pending_list);
+		}
+	}
+
+	list_for_each_entry_safe(t, tmp, &pending_list, link) {
+		list_del(&t->link);
+
+		if (!t->with_tstamp) {
+			t->callback.without_tstamp(card, RCODE_CANCELLED, NULL, 0,
+						   t->callback_data);
+		} else {
+			t->callback.with_tstamp(card, RCODE_CANCELLED, t->packet.timestamp, 0,
+						NULL, 0, t->callback_data);
+		}
+	}
+}
+
 // card->transactions.lock must be acquired in advance.
 #define find_and_pop_transaction_entry(card, condition)			\
 ({									\
diff --git a/drivers/firewire/core.h b/drivers/firewire/core.h
index 903812b6bb3f..41fb39d9a4e6 100644
--- a/drivers/firewire/core.h
+++ b/drivers/firewire/core.h
@@ -287,6 +287,8 @@ void fw_fill_response(struct fw_packet *response, u32 *request_header,
 void fw_request_get(struct fw_request *request);
 void fw_request_put(struct fw_request *request);
 
+void fw_cancel_pending_transactions(struct fw_card *card);
+
 // Convert the value of IEEE 1394 CYCLE_TIME register to the format of timeStamp field in
 // descriptors of 1394 OHCI.
 static inline u32 cycle_time_to_ohci_tstamp(u32 tstamp)
diff --git a/drivers/firewire/ohci.c b/drivers/firewire/ohci.c
index 0625d11dbd74..e3e78dc42530 100644
--- a/drivers/firewire/ohci.c
+++ b/drivers/firewire/ohci.c
@@ -3719,11 +3719,6 @@ static void pci_remove(struct pci_dev *dev)
 
 	fw_core_remove_card(&ohci->card);
 
-	/*
-	 * FIXME: Fail all pending packets here, now that the upper
-	 * layers can't queue any more.
-	 */
-
 	software_reset(ohci);
 
 	irq = pci_irq_vector(dev, 0);
-- 
2.51.0