Re: sky2 panic in 2.6.32.1 under load (new oops)

From: Michael Breuer
Date: Tue Dec 29 2009 - 13:38:44 EST


The frequency of the errors is reduced, but in place I'm seeing a large number of DHCPINFORM/DHCPACK to/from the system from which I'm generating load.

It appears that it's now taking a higher throughput to cause the interrupt status errors than without this patch, but they're still occurring. Just for fun, I'll try without this patch and with VT-D disabled later today.


On 12/29/2009 12:30 PM, Stephen Hemminger wrote:
There could be DMA problems, either because chip isn't remembering
upper address, or because of lack of wires from chip to memory controller;
there have been problems on motherboards where I/O devices couldn't access
all of memory.

Try this, it forces each transmit to have full 64 bit address. It drops an
optimization that was done to reduce the number of transmit descriptors
used.

--- a/drivers/net/sky2.c 2009-12-29 09:23:37.114074275 -0800
+++ b/drivers/net/sky2.c 2009-12-29 09:26:38.699912035 -0800
@@ -1038,10 +1038,11 @@ static void tx_init(struct sky2_port *sk
sky2->tx_tcpsum = 0;
sky2->tx_last_mss = 0;

- le = get_tx_le(sky2,&sky2->tx_prod);
- le->addr = 0;
- le->opcode = OP_ADDR64 | HW_OWNER;
- sky2->tx_last_upper = 0;
+ if (sizeof(dma_addr_t) == sizeof(u32)) {
+ le = get_tx_le(sky2,&sky2->tx_prod);
+ le->addr = 0;
+ le->opcode = OP_ADDR64 | HW_OWNER;
+ }
}

/* Update chip's next pointer */
@@ -1669,10 +1670,9 @@ static netdev_tx_t sky2_xmit_frame(struc

/* Send high bits if needed */
upper = upper_32_bits(mapping);
- if (upper != sky2->tx_last_upper) {
+ if (sizeof(mapping)> sizeof(u32)) {
le = get_tx_le(sky2,&slot);
le->addr = cpu_to_le32(upper);
- sky2->tx_last_upper = upper;
le->opcode = OP_ADDR64 | HW_OWNER;
}

@@ -1762,10 +1762,9 @@ static netdev_tx_t sky2_xmit_frame(struc
goto mapping_unwind;

upper = upper_32_bits(mapping);
- if (upper != sky2->tx_last_upper) {
+ if (sizeof(mapping)> sizeof(u32)) {
le = get_tx_le(sky2,&slot);
le->addr = cpu_to_le32(upper);
- sky2->tx_last_upper = upper;
le->opcode = OP_ADDR64 | HW_OWNER;
}

--- a/drivers/net/sky2.h 2009-12-29 09:23:37.164072886 -0800
+++ b/drivers/net/sky2.h 2009-12-29 09:25:15.302197993 -0800
@@ -2191,7 +2191,6 @@ struct sky2_port {

u16 tx_pending;
u16 tx_last_mss;
- u32 tx_last_upper;
u32 tx_tcpsum;

struct rx_ring_info *rx_ring ____cacheline_aligned_in_smp;

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