Commit 880f8f99 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

bnx2x: allow bnx2x_bsc_read() to schedule 



bnx2x_warpcore_read_sfp_module_eeprom() can call bnx2x_bsc_read()
three times before giving up.

This causes latency blips of at least 31 ms (58 ms being reported
by our teams)

Convert the long lasting loops of udelay() to usleep_range() ones,
and breaks the loops on precise time tracking.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Ariel Elior <aelior@marvell.com>
Cc: Sudarsana Kalluru <skalluru@marvell.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6a1015b0

drivers/net/ethernet/broadcom/bnx2x/bnx2x_link.c

+15 −11
Original line number Diff line number Diff line
@@ -3085,6 +3085,7 @@ static int bnx2x_bsc_read(struct link_params *params, 
			  u8 xfer_cnt,

			  u32 *data_array)

{

	u64 t0, delta;

	u32 val, i;

	int rc = 0;
@@ -3114,17 +3115,18 @@ static int bnx2x_bsc_read(struct link_params *params, 
	REG_WR(bp, MCP_REG_MCPR_IMC_COMMAND, val);



	/* Poll for completion */

	i = 0;

	t0 = ktime_get_ns();

	val = REG_RD(bp, MCP_REG_MCPR_IMC_COMMAND);

	while (((val >> MCPR_IMC_COMMAND_IMC_STATUS_BITSHIFT) & 0x3) != 1) {

		udelay(10);

		val = REG_RD(bp, MCP_REG_MCPR_IMC_COMMAND);

		if (i++ > 1000) {

			DP(NETIF_MSG_LINK, "wr 0 byte timed out after %d try\n",

								i);

		delta = ktime_get_ns() - t0;

		if (delta > 10 * NSEC_PER_MSEC) {

			DP(NETIF_MSG_LINK, "wr 0 byte timed out after %Lu ns\n",

					   delta);

			rc = -EFAULT;

			break;

		}

		usleep_range(10, 20);

		val = REG_RD(bp, MCP_REG_MCPR_IMC_COMMAND);

	}

	if (rc == -EFAULT)

		return rc;
@@ -3138,16 +3140,18 @@ static int bnx2x_bsc_read(struct link_params *params, 
	REG_WR(bp, MCP_REG_MCPR_IMC_COMMAND, val);



	/* Poll for completion */

	i = 0;

	t0 = ktime_get_ns();

	val = REG_RD(bp, MCP_REG_MCPR_IMC_COMMAND);

	while (((val >> MCPR_IMC_COMMAND_IMC_STATUS_BITSHIFT) & 0x3) != 1) {

		udelay(10);

		val = REG_RD(bp, MCP_REG_MCPR_IMC_COMMAND);

		if (i++ > 1000) {

			DP(NETIF_MSG_LINK, "rd op timed out after %d try\n", i);

		delta = ktime_get_ns() - t0;

		if (delta > 10 * NSEC_PER_MSEC) {

			DP(NETIF_MSG_LINK, "rd op timed out after %Lu ns\n",

					   delta);

			rc = -EFAULT;

			break;

		}

		usleep_range(10, 20);

		val = REG_RD(bp, MCP_REG_MCPR_IMC_COMMAND);

	}

	if (rc == -EFAULT)

		return rc;

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