[PATCH] ibmveth: Fix index increment calculation

The recent commit 751ae21c6c introduced a bug
in the producer/consumer index calculation in the ibmveth driver -
incautious use of the post-increment ++ operator resulted in an increment
being immediately reverted.  This patch corrects the logic.

Without this patch, the driver oopses almost immediately after activation
on at least some machines.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Acked-by: Santiago Leon <santil@us.ibm.com>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
David Gibson 2006-10-21 10:24:13 -07:00 коммит произвёл Linus Torvalds
Родитель d42552c3ac
Коммит 047a66d4bb
1 изменённых файлов: 6 добавлений и 4 удалений

Просмотреть файл

@ -212,8 +212,8 @@ static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter, struc
break; break;
} }
free_index = pool->consumer_index++ % pool->size; free_index = pool->consumer_index;
pool->consumer_index = free_index; pool->consumer_index = (pool->consumer_index + 1) % pool->size;
index = pool->free_map[free_index]; index = pool->free_map[free_index];
ibmveth_assert(index != IBM_VETH_INVALID_MAP); ibmveth_assert(index != IBM_VETH_INVALID_MAP);
@ -329,8 +329,10 @@ static void ibmveth_remove_buffer_from_pool(struct ibmveth_adapter *adapter, u64
adapter->rx_buff_pool[pool].buff_size, adapter->rx_buff_pool[pool].buff_size,
DMA_FROM_DEVICE); DMA_FROM_DEVICE);
free_index = adapter->rx_buff_pool[pool].producer_index++ % adapter->rx_buff_pool[pool].size; free_index = adapter->rx_buff_pool[pool].producer_index;
adapter->rx_buff_pool[pool].producer_index = free_index; adapter->rx_buff_pool[pool].producer_index
= (adapter->rx_buff_pool[pool].producer_index + 1)
% adapter->rx_buff_pool[pool].size;
adapter->rx_buff_pool[pool].free_map[free_index] = index; adapter->rx_buff_pool[pool].free_map[free_index] = index;
mb(); mb();