cxgb3: disable high freq non-data interrupts
Under RX pressure, The HW might generate a high load of interrupts
to signal mac fifo or free lists overflow.
Disable the interrupts, and poll the relevant status bits
to maintain stats.
Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/cxgb3/t3_hw.c b/drivers/net/cxgb3/t3_hw.c
index ac2a974..7c6ee0c 100644
--- a/drivers/net/cxgb3/t3_hw.c
+++ b/drivers/net/cxgb3/t3_hw.c
@@ -1323,7 +1323,7 @@
#define MC7_INTR_MASK (F_AE | F_UE | F_CE | V_PE(M_PE))
#define XGM_INTR_MASK (V_TXFIFO_PRTY_ERR(M_TXFIFO_PRTY_ERR) | \
V_RXFIFO_PRTY_ERR(M_RXFIFO_PRTY_ERR) | \
- F_TXFIFO_UNDERRUN | F_RXFIFO_OVERFLOW)
+ F_TXFIFO_UNDERRUN)
#define PCIX_INTR_MASK (F_MSTDETPARERR | F_SIGTARABT | F_RCVTARABT | \
F_RCVMSTABT | F_SIGSYSERR | F_DETPARERR | \
F_SPLCMPDIS | F_UNXSPLCMP | F_RCVSPLCMPERR | \
@@ -1695,7 +1695,14 @@
static int mac_intr_handler(struct adapter *adap, unsigned int idx)
{
struct cmac *mac = &adap2pinfo(adap, idx)->mac;
- u32 cause = t3_read_reg(adap, A_XGM_INT_CAUSE + mac->offset);
+ /*
+ * We mask out interrupt causes for which we're not taking interrupts.
+ * This allows us to use polling logic to monitor some of the other
+ * conditions when taking interrupts would impose too much load on the
+ * system.
+ */
+ u32 cause = t3_read_reg(adap, A_XGM_INT_CAUSE + mac->offset) &
+ ~F_RXFIFO_OVERFLOW;
if (cause & V_TXFIFO_PRTY_ERR(M_TXFIFO_PRTY_ERR)) {
mac->stats.tx_fifo_parity_err++;
@@ -3617,7 +3624,15 @@
adapter->params.info = ai;
adapter->params.nports = ai->nports;
adapter->params.rev = t3_read_reg(adapter, A_PL_REV);
- adapter->params.linkpoll_period = 0;
+ /*
+ * We used to only run the "adapter check task" once a second if
+ * we had PHYs which didn't support interrupts (we would check
+ * their link status once a second). Now we check other conditions
+ * in that routine which could potentially impose a very high
+ * interrupt load on the system. As such, we now always scan the
+ * adapter state once a second ...
+ */
+ adapter->params.linkpoll_period = 10;
adapter->params.stats_update_period = is_10G(adapter) ?
MAC_STATS_ACCUM_SECS : (MAC_STATS_ACCUM_SECS * 10);
adapter->params.pci.vpd_cap_addr =
@@ -3707,7 +3722,14 @@
ETH_ALEN);
init_link_config(&p->link_config, p->phy.caps);
p->phy.ops->power_down(&p->phy, 1);
- if (!(p->phy.caps & SUPPORTED_IRQ))
+
+ /*
+ * If the PHY doesn't support interrupts for link status
+ * changes, schedule a scan of the adapter links at least
+ * once a second.
+ */
+ if (!(p->phy.caps & SUPPORTED_IRQ) &&
+ adapter->params.linkpoll_period > 10)
adapter->params.linkpoll_period = 10;
}