amd-xgbe: Remove Tx coalescing
The Tx coalescing support in the driver was a software implementation
for something lacking in the hardware. Using hrtimers, the idea was to
trigger a timer interrupt after having queued a packet for transmit.
Unfortunately, as the timer value was lowered, the timer expired before
the hardware actually did the transmit and so it was racey and resulted
in unnecessary interrupts.
Remove the Tx coalescing support and hrtimer and replace with a Tx timer
that is used as a reclaim timer in case of inactivity.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
index e165d06..80dd7a9 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-dev.c
@@ -1367,12 +1367,11 @@
XGMAC_DMA_IOWRITE(channel, DMA_CH_TDTR_LO,
lower_32_bits(rdata->rdesc_dma));
- /* Start the Tx coalescing timer */
+ /* Start the Tx timer */
if (pdata->tx_usecs && !channel->tx_timer_active) {
channel->tx_timer_active = 1;
- hrtimer_start(&channel->tx_timer,
- ktime_set(0, pdata->tx_usecs * NSEC_PER_USEC),
- HRTIMER_MODE_REL);
+ mod_timer(&channel->tx_timer,
+ jiffies + usecs_to_jiffies(pdata->tx_usecs));
}
ring->tx.xmit_more = 0;
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
index ef4625e..122a631 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-drv.c
@@ -411,11 +411,9 @@
return IRQ_HANDLED;
}
-static enum hrtimer_restart xgbe_tx_timer(struct hrtimer *timer)
+static void xgbe_tx_timer(unsigned long data)
{
- struct xgbe_channel *channel = container_of(timer,
- struct xgbe_channel,
- tx_timer);
+ struct xgbe_channel *channel = (struct xgbe_channel *)data;
struct xgbe_prv_data *pdata = channel->pdata;
struct napi_struct *napi;
@@ -437,8 +435,6 @@
channel->tx_timer_active = 0;
DBGPR("<--xgbe_tx_timer\n");
-
- return HRTIMER_NORESTART;
}
static void xgbe_init_tx_timers(struct xgbe_prv_data *pdata)
@@ -454,9 +450,8 @@
break;
DBGPR(" %s adding tx timer\n", channel->name);
- hrtimer_init(&channel->tx_timer, CLOCK_MONOTONIC,
- HRTIMER_MODE_REL);
- channel->tx_timer.function = xgbe_tx_timer;
+ setup_timer(&channel->tx_timer, xgbe_tx_timer,
+ (unsigned long)channel);
}
DBGPR("<--xgbe_init_tx_timers\n");
@@ -475,8 +470,7 @@
break;
DBGPR(" %s deleting tx timer\n", channel->name);
- channel->tx_timer_active = 0;
- hrtimer_cancel(&channel->tx_timer);
+ del_timer_sync(&channel->tx_timer);
}
DBGPR("<--xgbe_stop_tx_timers\n");
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c b/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c
index 43e5571..376d6a5 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c
+++ b/drivers/net/ethernet/amd/xgbe/xgbe-ethtool.c
@@ -388,7 +388,6 @@
ec->rx_coalesce_usecs = hw_if->riwt_to_usec(pdata, riwt);
ec->rx_max_coalesced_frames = pdata->rx_frames;
- ec->tx_coalesce_usecs = pdata->tx_usecs;
ec->tx_max_coalesced_frames = pdata->tx_frames;
DBGPR("<--xgbe_get_coalesce\n");
@@ -402,13 +401,14 @@
struct xgbe_prv_data *pdata = netdev_priv(netdev);
struct xgbe_hw_if *hw_if = &pdata->hw_if;
unsigned int rx_frames, rx_riwt, rx_usecs;
- unsigned int tx_frames, tx_usecs;
+ unsigned int tx_frames;
DBGPR("-->xgbe_set_coalesce\n");
/* Check for not supported parameters */
if ((ec->rx_coalesce_usecs_irq) ||
(ec->rx_max_coalesced_frames_irq) ||
+ (ec->tx_coalesce_usecs) ||
(ec->tx_coalesce_usecs_irq) ||
(ec->tx_max_coalesced_frames_irq) ||
(ec->stats_block_coalesce_usecs) ||
@@ -457,7 +457,6 @@
return -EINVAL;
}
- tx_usecs = ec->tx_coalesce_usecs;
tx_frames = ec->tx_max_coalesced_frames;
/* Check the bounds of values for Tx */
@@ -471,7 +470,6 @@
pdata->rx_frames = rx_frames;
hw_if->config_rx_coalesce(pdata);
- pdata->tx_usecs = tx_usecs;
pdata->tx_frames = tx_frames;
hw_if->config_tx_coalesce(pdata);
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h
index bfe11fb..72b8f27 100644
--- a/drivers/net/ethernet/amd/xgbe/xgbe.h
+++ b/drivers/net/ethernet/amd/xgbe/xgbe.h
@@ -222,7 +222,7 @@
((_idx) & ((_ring)->rdesc_count - 1)))
/* Default coalescing parameters */
-#define XGMAC_INIT_DMA_TX_USECS 50
+#define XGMAC_INIT_DMA_TX_USECS 1000
#define XGMAC_INIT_DMA_TX_FRAMES 25
#define XGMAC_MAX_DMA_RIWT 0xff
@@ -410,7 +410,7 @@
unsigned int saved_ier;
unsigned int tx_timer_active;
- struct hrtimer tx_timer;
+ struct timer_list tx_timer;
struct xgbe_ring *tx_ring;
struct xgbe_ring *rx_ring;