Hello,
I posted below RFC to the linux-can ML, but it might be actually
more appropriate for netdev (since it involves napi). This driver
is lying a bit about the amount of work done. Changing that (always
look at work done instead of the hw state) seems to solve the issue,
but I have no clear understanding why that is (and why it takes down
the ethernet stack as well).
If someone has suggestions / ideas on what to check, please let me
know.
Regards,
Jeroen
The mail send to linux-can:
While updating to Linux 4.9.93, the ti_hecc causes several problems. One
of them is that under high load on the CAN-bus and ethernet, the ethernet
connection completely stalls and won't recover. The patch below seems to
fix that (as in read as much as we can and always re-enable interrupts,
it will poll again thereafter).
It would be appreciated if someone more familiar with this code can
comment on it.
Thanks in advance,
Jeroen
--- a/drivers/net/can/ti_hecc.c
+++ b/drivers/net/can/ti_hecc.c
@@ -625,20 +625,16 @@ static int ti_hecc_rx_poll(struct napi_struct
*napi, int quota)
spin_unlock_irqrestore(&priv->mbx_lock, flags);
} else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) {
priv->rx_next = HECC_RX_FIRST_MBOX;
- break;
}
}
/* Enable packet interrupt if all pkts are handled */
- if (hecc_read(priv, HECC_CANRMP) == 0) {
+ if (num_pkts < quota) {
napi_complete(napi);
/* Re-enable RX mailbox interrupts */
mbx_mask = hecc_read(priv, HECC_CANMIM);
mbx_mask |= HECC_TX_MBOX_MASK;
hecc_write(priv, HECC_CANMIM, mbx_mask);
- } else {
- /* repoll is done only if whole budget is used */
- num_pkts = quota;
}
