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authorStefan Richter <stefanr@s5r6.in-berlin.de>2008-01-25 18:57:41 +0100
committerStefan Richter <stefanr@s5r6.in-berlin.de>2008-01-30 22:22:27 +0100
commitb5d2a5e04e6a26cb3f77af8cbc31e74c361d706c (patch)
treecfc3b2dc141f643bcf6ef065cca802340b335799 /drivers/firewire/fw-topology.c
parentcf5a56ac8083dd04ffe8b9b2ec7895e9bcff44bc (diff)
firewire: enforce access order between generation and node ID, fix "giving up on config rom"
fw_device.node_id and fw_device.generation are accessed without mutexes. We have to ensure that all readers will get to see node_id updates before generation updates. Fixes an inability to recognize devices after "giving up on config rom", https://bugzilla.redhat.com/show_bug.cgi?id=429950 Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Reviewed by Nick Piggin <nickpiggin@yahoo.com.au>. Verified to fix 'giving up on config rom' issues on multiple system and drive combinations that were previously affected. Signed-off-by: Jarod Wilson <jwilson@redhat.com> Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Diffstat (limited to 'drivers/firewire/fw-topology.c')
-rw-r--r--drivers/firewire/fw-topology.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c
index 0fc9b000e99d..172c1867e9aa 100644
--- a/drivers/firewire/fw-topology.c
+++ b/drivers/firewire/fw-topology.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/wait.h>
#include <linux/errno.h>
+#include <asm/system.h>
#include "fw-transaction.h"
#include "fw-topology.h"
@@ -518,6 +519,11 @@ fw_core_handle_bus_reset(struct fw_card *card,
card->bm_retries = 0;
card->node_id = node_id;
+ /*
+ * Update node_id before generation to prevent anybody from using
+ * a stale node_id together with a current generation.
+ */
+ smp_wmb();
card->generation = generation;
card->reset_jiffies = jiffies;
schedule_delayed_work(&card->work, 0);