[PATCH] firewire: core: do not disable local IRQs while handling requests

Stefan Richter
2012-02-18T19:42:17Z

fw_core_handle_request() is called by the low-level driver in tasklet
context or process context, and fw_core_add/remove_address_handler() is
called by mid- or high-level code in process context. So convert
address_handler_lock accesses from those which disable local IRQs to
ones which just disable local softIRQs.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
---
Only lightly tested without lockdep; I have yet to boot back into a
lockdep-enabled kernel.

Also to do: Convert accesses of other locks of this kind, e.g. in
isochronous I/O handlers, and convert high-level code too.

drivers/firewire/core-transaction.c | 21 ++++++++-------------
1 file changed, 8 insertions(+), 13 deletions(-)

--- a/drivers/firewire/core-transaction.c
+++ b/drivers/firewire/core-transaction.c
@@ -565,7 +565,6 @@ int fw_core_add_address_handler(struct f
const struct fw_address_region *region)
{
struct fw_address_handler *other;
- unsigned long flags;
int ret = -EBUSY;

if (region->start & 0xffff000000000003ULL ||
@@ -575,7 +574,7 @@ int fw_core_add_address_handler(struct f
handler->length == 0)
return -EINVAL;

- spin_lock_irqsave(&address_handler_lock, flags);
+ spin_lock_bh(&address_handler_lock);

handler->offset = region->start;
while (handler->offset + handler->length <= region->end) {
@@ -594,7 +593,7 @@ int fw_core_add_address_handler(struct f
}
}

- spin_unlock_irqrestore(&address_handler_lock, flags);
+ spin_unlock_bh(&address_handler_lock);

return ret;
}
@@ -608,11 +607,9 @@ EXPORT_SYMBOL(fw_core_add_address_handle
*/
void fw_core_remove_address_handler(struct fw_address_handler *handler)
{
- unsigned long flags;
-
- spin_lock_irqsave(&address_handler_lock, flags);
+ spin_lock_bh(&address_handler_lock);
list_del(&handler->link);
- spin_unlock_irqrestore(&address_handler_lock, flags);
+ spin_unlock_bh(&address_handler_lock);
}
EXPORT_SYMBOL(fw_core_remove_address_handler);

@@ -829,7 +826,6 @@ static void handle_exclusive_region_requ
unsigned long long offset)
{
struct fw_address_handler *handler;
- unsigned long flags;
int tcode, destination, source;

destination = HEADER_GET_DESTINATION(p->header[0]);
@@ -838,7 +834,7 @@ static void handle_exclusive_region_requ
if (tcode == TCODE_LOCK_REQUEST)
tcode = 0x10 + HEADER_GET_EXTENDED_TCODE(p->header[3]);

- spin_lock_irqsave(&address_handler_lock, flags);
+ spin_lock_bh(&address_handler_lock);
handler = lookup_enclosing_address_handler(&address_handler_list,
offset, request->length);
if (handler)
@@ -847,7 +843,7 @@ static void handle_exclusive_region_requ
p->generation, offset,
request->data, request->length,
handler->callback_data);
- spin_unlock_irqrestore(&address_handler_lock, flags);
+ spin_unlock_bh(&address_handler_lock);

if (!handler)
fw_send_response(card, request, RCODE_ADDRESS_ERROR);
@@ -859,7 +855,6 @@ static void handle_fcp_region_request(st
unsigned long long offset)
{
struct fw_address_handler *handler;
- unsigned long flags;
int tcode, destination, source;

if ((offset != (CSR_REGISTER_BASE | CSR_FCP_COMMAND) &&
@@ -881,7 +876,7 @@ static void handle_fcp_region_request(st
return;
}

- spin_lock_irqsave(&address_handler_lock, flags);
+ spin_lock_bh(&address_handler_lock);
list_for_each_entry(handler, &address_handler_list, link) {
if (is_enclosing_handler(handler, offset, request->length))
handler->address_callback(card, NULL, tcode,
@@ -891,7 +886,7 @@ static void handle_fcp_region_request(st
request->length,
handler->callback_data);
}
- spin_unlock_irqrestore(&address_handler_lock, flags);
+ spin_unlock_bh(&address_handler_lock);

fw_send_response(card, request, RCODE_COMPLETE);
}