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author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-01-25 20:57:41 +0300 |
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committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2008-01-31 00:22:27 +0300 |
commit | b5d2a5e04e6a26cb3f77af8cbc31e74c361d706c (patch) | |
tree | cfc3b2dc141f643bcf6ef065cca802340b335799 /drivers/firewire/fw-topology.c | |
parent | cf5a56ac8083dd04ffe8b9b2ec7895e9bcff44bc (diff) | |
download | linux-b5d2a5e04e6a26cb3f77af8cbc31e74c361d706c.tar.xz |
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.c | 6 |
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); |