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authorStefan Richter <stefanr@s5r6.in-berlin.de>2008-03-24 20:56:40 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2009-01-20 19:29:51 +0100
commit8cd0bbbdff7471163cc6a058be8b8610ddd01d6b (patch)
treede25f60d599ddef9a0ee88357dc418dbdf95b51d
parenta5c7f4710fba334bf613d705f97b4471b36446f8 (diff)
downloadblackbird-obmc-linux-8cd0bbbdff7471163cc6a058be8b8610ddd01d6b.tar.gz
blackbird-obmc-linux-8cd0bbbdff7471163cc6a058be8b8610ddd01d6b.zip
firewire: unnecessary BM delay after generation rollover
Noticed by Jarod Wilson: The bus manager work was unnecessarily delayed each time the bus generation counter rolled over. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Jarod Wilson <jwilson@redhat.com>
-rw-r--r--drivers/firewire/fw-card.c2
-rw-r--r--drivers/firewire/fw-topology.c2
-rw-r--r--drivers/firewire/fw-transaction.h9
3 files changed, 11 insertions, 2 deletions
diff --git a/drivers/firewire/fw-card.c b/drivers/firewire/fw-card.c
index 6bd91a15d5e6..17a80cecdc14 100644
--- a/drivers/firewire/fw-card.c
+++ b/drivers/firewire/fw-card.c
@@ -232,7 +232,7 @@ fw_card_bm_work(struct work_struct *work)
root_id = root_node->node_id;
grace = time_after(jiffies, card->reset_jiffies + DIV_ROUND_UP(HZ, 10));
- if (card->bm_generation + 1 == generation ||
+ if (is_next_generation(generation, card->bm_generation) ||
(card->bm_generation != generation && grace)) {
/*
* This first step is to figure out who is IRM and
diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c
index e7520e4bd6bc..8dd6703b55cd 100644
--- a/drivers/firewire/fw-topology.c
+++ b/drivers/firewire/fw-topology.c
@@ -523,7 +523,7 @@ fw_core_handle_bus_reset(struct fw_card *card,
* previously processed one, we cannot reliably compare the
* old and new topologies.
*/
- if ((generation & 0xff) != ((card->generation + 1) & 0xff) &&
+ if (!is_next_generation(generation, card->generation) &&
card->local_node != NULL) {
fw_notify("skipped bus generations, destroying all nodes\n");
fw_destroy_nodes(card);
diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h
index c9ab12a15f6e..1d78e9cc5940 100644
--- a/drivers/firewire/fw-transaction.h
+++ b/drivers/firewire/fw-transaction.h
@@ -276,6 +276,15 @@ static inline void fw_card_put(struct fw_card *card)
extern void fw_schedule_bm_work(struct fw_card *card, unsigned long delay);
/*
+ * Check whether new_generation is the immediate successor of old_generation.
+ * Take counter roll-over at 255 (as per to OHCI) into account.
+ */
+static inline bool is_next_generation(int new_generation, int old_generation)
+{
+ return (new_generation & 0xff) == ((old_generation + 1) & 0xff);
+}
+
+/*
* The iso packet format allows for an immediate header/payload part
* stored in 'header' immediately after the packet info plus an
* indirect payload part that is pointer to by the 'payload' field.
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