firewire: reread config ROM when device reset the bus
When a device changes its configuration ROM, it announces this with a
bus reset. firewire-core has to check which node initiated a bus reset
and whether any unit directories went away or were added on this node.
Tested with an IOI FWB-IDE01AB which has its link-on bit set if bus
power is available but does not respond to ROM read requests if self
power is off. This implements
- recognition of the units if self power is switched on after fw-core
gave up the initial attempt to read the config ROM,
- shutdown of the units when self power is switched off.
Also tested with a second PC running Linux/ieee1394. When the eth1394
driver is inserted and removed on that node, fw-core now notices the
addition and removal of the IPv4 unit on the ieee1394 node.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index 46bc197..4a54192 100644
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -269,21 +269,28 @@
{
struct fw_cdev_get_info *get_info = buffer;
struct fw_cdev_event_bus_reset bus_reset;
+ unsigned long ret = 0;
client->version = get_info->version;
get_info->version = FW_CDEV_VERSION;
+ down_read(&fw_device_rwsem);
+
if (get_info->rom != 0) {
void __user *uptr = u64_to_uptr(get_info->rom);
size_t want = get_info->rom_length;
size_t have = client->device->config_rom_length * 4;
- if (copy_to_user(uptr, client->device->config_rom,
- min(want, have)))
- return -EFAULT;
+ ret = copy_to_user(uptr, client->device->config_rom,
+ min(want, have));
}
get_info->rom_length = client->device->config_rom_length * 4;
+ up_read(&fw_device_rwsem);
+
+ if (ret != 0)
+ return -EFAULT;
+
client->bus_reset_closure = get_info->bus_reset_closure;
if (get_info->bus_reset != 0) {
void __user *uptr = u64_to_uptr(get_info->bus_reset);
