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Commit 8beb79b7 authored by Harini Katakam's avatar Harini Katakam Committed by David S. Miller
Browse files

net: macb: Check MDIO state before read/write and use timeouts 



Replace the while loop in MDIO read/write functions with a timeout.
In addition, add a check for MDIO bus busy before initiating a new
operation as well to make sure there is no ongoing MDIO operation.

Signed-off-by: default avatarShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: default avatarSai Pavan Boddu <sai.pavan.boddu@xilinx.com>
Signed-off-by: default avatarHarini Katakam <harini.katakam@xilinx.com>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 41bc0ddb

drivers/net/ethernet/cadence/macb.h

+2 −0
Original line number Diff line number Diff line
@@ -715,6 +715,8 @@ 
		__v; \

	})



#define MACB_READ_NSR(bp)	macb_readl(bp, NSR)



/* struct macb_dma_desc - Hardware DMA descriptor

 * @addr: DMA address of data buffer

 * @ctrl: Control and status bits

drivers/net/ethernet/cadence/macb_main.c

+27 −6
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ 
#include <linux/ip.h>

#include <linux/udp.h>

#include <linux/tcp.h>

#include <linux/iopoll.h>

#include "macb.h"



#define MACB_RX_BUFFER_SIZE	128
@@ -79,6 +80,8 @@ 
 */

#define MACB_HALT_TIMEOUT	1230



#define MACB_MDIO_TIMEOUT	1000000 /* in usecs */



/* DMA buffer descriptor might be different size

 * depends on hardware configuration:

 *
@@ -318,10 +321,23 @@ static void macb_get_hwaddr(struct macb *bp) 
	eth_hw_addr_random(bp->dev);

}



static int macb_mdio_wait_for_idle(struct macb *bp)

{

	u32 val;



	return readx_poll_timeout(MACB_READ_NSR, bp, val, val & MACB_BIT(IDLE),

				  1, MACB_MDIO_TIMEOUT);

}



static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum)

{

	struct macb *bp = bus->priv;

	int value;

	int err;



	err = macb_mdio_wait_for_idle(bp);

	if (err < 0)

		return err;



	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)

			      | MACB_BF(RW, MACB_MAN_READ)
@@ -329,9 +345,9 @@ static int macb_mdio_read(struct mii_bus *bus, int mii_id, int regnum) 
			      | MACB_BF(REGA, regnum)

			      | MACB_BF(CODE, MACB_MAN_CODE)));



	/* wait for end of transfer */

	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))

		cpu_relax();

	err = macb_mdio_wait_for_idle(bp);

	if (err < 0)

		return err;



	value = MACB_BFEXT(DATA, macb_readl(bp, MAN));
@@ -342,6 +358,11 @@ static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum, 
			   u16 value)

{

	struct macb *bp = bus->priv;

	int err;



	err = macb_mdio_wait_for_idle(bp);

	if (err < 0)

		return err;



	macb_writel(bp, MAN, (MACB_BF(SOF, MACB_MAN_SOF)

			      | MACB_BF(RW, MACB_MAN_WRITE)
@@ -350,9 +371,9 @@ static int macb_mdio_write(struct mii_bus *bus, int mii_id, int regnum, 
			      | MACB_BF(CODE, MACB_MAN_CODE)

			      | MACB_BF(DATA, value)));



	/* wait for end of transfer */

	while (!MACB_BFEXT(IDLE, macb_readl(bp, NSR)))

		cpu_relax();

	err = macb_mdio_wait_for_idle(bp);

	if (err < 0)

		return err;



	return 0;

}