Commit 7b581a0f authored by Divy Le Ray's avatar Divy Le Ray Committed by Jeff Garzik
Browse files

cxgb3 - Stop mac RX when changing MTU 



Rx traffic needs to be halted when the MTU is changed
to avoid a potential chip hang.
Reset/restore MAC filters around a MTU change.
Also fix the pause frames high materwark setting.

Signed-off-by: default avatarDivy Le Ray <divy@chelsio.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent c706bfb5

drivers/net/cxgb3/regs.h

+4 −0
Original line number Diff line number Diff line
@@ -1882,6 +1882,10 @@ 
#define V_COPYALLFRAMES(x) ((x) << S_COPYALLFRAMES)

#define F_COPYALLFRAMES    V_COPYALLFRAMES(1U)



#define S_DISBCAST    1

#define V_DISBCAST(x) ((x) << S_DISBCAST)

#define F_DISBCAST    V_DISBCAST(1U)



#define A_XGM_RX_HASH_LOW 0x814



#define A_XGM_RX_HASH_HIGH 0x818

drivers/net/cxgb3/xgmac.c

+66 −1
Original line number Diff line number Diff line
@@ -231,6 +231,28 @@ int t3_mac_set_num_ucast(struct cmac *mac, int n) 
	return 0;

}



static void disable_exact_filters(struct cmac *mac)

{

	unsigned int i, reg = mac->offset + A_XGM_RX_EXACT_MATCH_LOW_1;



	for (i = 0; i < EXACT_ADDR_FILTERS; i++, reg += 8) {

		u32 v = t3_read_reg(mac->adapter, reg);

		t3_write_reg(mac->adapter, reg, v);

	}

	t3_read_reg(mac->adapter, A_XGM_RX_EXACT_MATCH_LOW_1);	/* flush */

}



static void enable_exact_filters(struct cmac *mac)

{

	unsigned int i, reg = mac->offset + A_XGM_RX_EXACT_MATCH_HIGH_1;



	for (i = 0; i < EXACT_ADDR_FILTERS; i++, reg += 8) {

		u32 v = t3_read_reg(mac->adapter, reg);

		t3_write_reg(mac->adapter, reg, v);

	}

	t3_read_reg(mac->adapter, A_XGM_RX_EXACT_MATCH_LOW_1);	/* flush */

}



/* Calculate the RX hash filter index of an Ethernet address */

static int hash_hw_addr(const u8 * addr)

{
@@ -281,6 +303,14 @@ int t3_mac_set_rx_mode(struct cmac *mac, struct t3_rx_mode *rm) 
	return 0;

}



static int rx_fifo_hwm(int mtu)

{

	int hwm;



	hwm = max(MAC_RXFIFO_SIZE - 3 * mtu, (MAC_RXFIFO_SIZE * 38) / 100);

	return min(hwm, MAC_RXFIFO_SIZE - 8192);

}



int t3_mac_set_mtu(struct cmac *mac, unsigned int mtu)

{

	int hwm, lwm;
@@ -306,11 +336,38 @@ int t3_mac_set_mtu(struct cmac *mac, unsigned int mtu) 
	lwm = min(3 * (int)mtu, MAC_RXFIFO_SIZE / 4);



	v = t3_read_reg(adap, A_XGM_RXFIFO_CFG + mac->offset);

	if (adap->params.rev == T3_REV_B2 &&

	    (t3_read_reg(adap, A_XGM_RX_CTRL + mac->offset) & F_RXEN)) {

		disable_exact_filters(mac);

		t3_set_reg_field(adap, A_XGM_RXFIFO_CFG + mac->offset,

				 F_ENHASHMCAST | F_COPYALLFRAMES, F_DISBCAST);



		/* drain rx FIFO */

		if (t3_wait_op_done(adap,

				    A_XGM_RX_MAX_PKT_SIZE_ERR_CNT +

				    mac->offset,

				    1 << 31, 1, 20, 5)) {

			t3_write_reg(adap, A_XGM_RXFIFO_CFG + mac->offset, v);

			enable_exact_filters(mac);

			return -EIO;

		}

		t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset, mtu);

		enable_exact_filters(mac);

	} else

		t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset, mtu);



	/*

	 * Adjust the PAUSE frame watermarks.  We always set the LWM, and the

	 * HWM only if flow-control is enabled.

	 */

	hwm = rx_fifo_hwm(mtu);

	lwm = min(3 * (int)mtu, MAC_RXFIFO_SIZE / 4);

	v &= ~V_RXFIFOPAUSELWM(M_RXFIFOPAUSELWM);

	v |= V_RXFIFOPAUSELWM(lwm / 8);

	if (G_RXFIFOPAUSEHWM(v))

		v = (v & ~V_RXFIFOPAUSEHWM(M_RXFIFOPAUSEHWM)) |

		    V_RXFIFOPAUSEHWM(hwm / 8);



	t3_write_reg(adap, A_XGM_RXFIFO_CFG + mac->offset, v);



	/* Adjust the TX FIFO threshold based on the MTU */
@@ -329,7 +386,6 @@ int t3_mac_set_mtu(struct cmac *mac, unsigned int mtu) 
			     (hwm - lwm) * 4 / 8);

	t3_write_reg(adap, A_XGM_TX_PAUSE_QUANTA + mac->offset,

		     MAC_RXFIFO_SIZE * 4 * 8 / 512);



	return 0;

}
@@ -357,6 +413,15 @@ int t3_mac_set_speed_duplex_fc(struct cmac *mac, int speed, int duplex, int fc) 
				 V_PORTSPEED(M_PORTSPEED), val);

	}



	val = t3_read_reg(adap, A_XGM_RXFIFO_CFG + oft);

	val &= ~V_RXFIFOPAUSEHWM(M_RXFIFOPAUSEHWM);

	if (fc & PAUSE_TX)

		val |= V_RXFIFOPAUSEHWM(rx_fifo_hwm(

						t3_read_reg(adap,

						A_XGM_RX_MAX_PKT_SIZE

						+ oft)) / 8);

	t3_write_reg(adap, A_XGM_RXFIFO_CFG + oft, val);



	t3_set_reg_field(adap, A_XGM_TX_CFG + oft, F_TXPAUSEEN,

			 (fc & PAUSE_RX) ? F_TXPAUSEEN : 0);

	return 0;