Messages in this thread Patch in this message | | | Date | Mon, 16 Oct 2006 11:43:34 +1000 | From | David Gibson <> | Subject | Re: Failed to boot kernel 2.6.19-rc2 due to IBM veth problem. |
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On Mon, Oct 16, 2006 at 12:26:37AM +0800, Yao Fei Zhu wrote: > Hi, all, > > Boot kernel 2.6.19-rc2 on IBM System P5 partitions will fall into xmon. > Here is the boot log,
This is probably the same bug I recently posted about. The patch below should fix it.
ibmveth: Fix index increment calculation
The recent commit 751ae21c6cd1493e3d0a4935b08fb298b9d89773 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>
Index: working-2.6/drivers/net/ibmveth.c =================================================================== --- working-2.6.orig/drivers/net/ibmveth.c 2006-10-13 14:19:54.000000000 +1000 +++ working-2.6/drivers/net/ibmveth.c 2006-10-13 14:19:59.000000000 +1000 @@ -212,8 +212,8 @@ static void ibmveth_replenish_buffer_poo break; } - free_index = pool->consumer_index++ % pool->size; - pool->consumer_index = free_index; + free_index = pool->consumer_index; + pool->consumer_index = (pool->consumer_index + 1) % pool->size; index = pool->free_map[free_index]; ibmveth_assert(index != IBM_VETH_INVALID_MAP); @@ -329,8 +329,10 @@ static void ibmveth_remove_buffer_from_p adapter->rx_buff_pool[pool].buff_size, DMA_FROM_DEVICE); - free_index = adapter->rx_buff_pool[pool].producer_index++ % adapter->rx_buff_pool[pool].size; - adapter->rx_buff_pool[pool].producer_index = free_index; + free_index = adapter->rx_buff_pool[pool].producer_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; mb();
-- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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