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Commit 7d350977 authored by Anton Vorontsov's avatar Anton Vorontsov Committed by David S. Miller
Browse files

gianfar: Implement workaround for eTSEC74 erratum 



MPC8313ECE says:

"If MACCFG2[Huge Frame]=0 and the Ethernet controller receives frames
 which are larger than MAXFRM, the controller truncates the frames to
 length MAXFRM and marks RxBD[TR]=1 to indicate the error. The controller
 also erroneously marks RxBD[TR]=1 if the received frame length is MAXFRM
 or MAXFRM-1, even though those frames are not truncated.
 No truncation or truncation error occurs if MACCFG2[Huge Frame]=1."

There are two options to workaround the issue:

"1. Set MACCFG2[Huge Frame]=1, so no truncation occurs for invalid large
 frames. Software can determine if a frame is larger than MAXFRM by
 reading RxBD[LG] or RxBD[Data Length].

 2. Set MAXFRM to 1538 (0x602) instead of the default 1536 (0x600), so
 normal-length frames are not marked as truncated. Software can examine
 RxBD[Data Length] to determine if the frame was larger than MAXFRM-2."

This patch implements the first workaround option by setting HUGEFRAME
bit, and gfar_clean_rx_ring() already checks the RxBD[Data Length].

Signed-off-by: default avatarAnton Vorontsov <avorontsov@mvista.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 70777d03

drivers/net/gianfar.c

+27 −2
Original line number Diff line number Diff line
@@ -85,6 +85,7 @@ 
#include <linux/net_tstamp.h>



#include <asm/io.h>

#include <asm/reg.h>

#include <asm/irq.h>

#include <asm/uaccess.h>

#include <linux/module.h>
@@ -928,6 +929,24 @@ static void gfar_init_filer_table(struct gfar_private *priv) 
	}

}



static void gfar_detect_errata(struct gfar_private *priv)

{

	struct device *dev = &priv->ofdev->dev;

	unsigned int pvr = mfspr(SPRN_PVR);

	unsigned int svr = mfspr(SPRN_SVR);

	unsigned int mod = (svr >> 16) & 0xfff6; /* w/o E suffix */

	unsigned int rev = svr & 0xffff;



	/* MPC8313 Rev 2.0 and higher; All MPC837x */

	if ((pvr == 0x80850010 && mod == 0x80b0 && rev >= 0x0020) ||

			(pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0))

		priv->errata |= GFAR_ERRATA_74;



	if (priv->errata)

		dev_info(dev, "enabled errata workarounds, flags: 0x%x\n",

			 priv->errata);

}



/* Set up the ethernet device structure, private data,

 * and anything else we need before we start */

static int gfar_probe(struct of_device *ofdev,
@@ -960,6 +979,8 @@ static int gfar_probe(struct of_device *ofdev, 
	dev_set_drvdata(&ofdev->dev, priv);

	regs = priv->gfargrp[0].regs;



	gfar_detect_errata(priv);



	/* Stop the DMA engine now, in case it was running before */

	/* (The firmware could have used it, and left it running). */

	gfar_halt(dev);
@@ -974,7 +995,10 @@ static int gfar_probe(struct of_device *ofdev, 
	gfar_write(&regs->maccfg1, tempval);



	/* Initialize MACCFG2. */

	gfar_write(&regs->maccfg2, MACCFG2_INIT_SETTINGS);

	tempval = MACCFG2_INIT_SETTINGS;

	if (gfar_has_errata(priv, GFAR_ERRATA_74))

		tempval |= MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK;

	gfar_write(&regs->maccfg2, tempval);



	/* Initialize ECNTRL */

	gfar_write(&regs->ecntrl, ECNTRL_INIT_SETTINGS);
@@ -2300,7 +2324,8 @@ static int gfar_change_mtu(struct net_device *dev, int new_mtu) 
	 * to allow huge frames, and to check the length */

	tempval = gfar_read(&regs->maccfg2);



	if (priv->rx_buffer_size > DEFAULT_RX_BUFFER_SIZE)

	if (priv->rx_buffer_size > DEFAULT_RX_BUFFER_SIZE ||

			gfar_has_errata(priv, GFAR_ERRATA_74))

		tempval |= (MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK);

	else

		tempval &= ~(MACCFG2_HUGEFRAME | MACCFG2_LENGTHCHECK);

drivers/net/gianfar.h

+11 −0
Original line number Diff line number Diff line
@@ -1025,6 +1025,10 @@ struct gfar_priv_grp { 
	char int_name_er[GFAR_INT_NAME_MAX];

};



enum gfar_errata {

	GFAR_ERRATA_74		= 0x01,

};



/* Struct stolen almost completely (and shamelessly) from the FCC enet source

 * (Ok, that's not so true anymore, but there is a family resemblence)

 * The GFAR buffer descriptors track the ring buffers.  The rx_bd_base
@@ -1049,6 +1053,7 @@ struct gfar_private { 
	struct device_node *node;

	struct net_device *ndev;

	struct of_device *ofdev;

	enum gfar_errata errata;



	struct gfar_priv_grp gfargrp[MAXGROUPS];

	struct gfar_priv_tx_q *tx_queue[MAX_TX_QS];
@@ -1111,6 +1116,12 @@ struct gfar_private { 
extern unsigned int ftp_rqfpr[MAX_FILER_IDX + 1];

extern unsigned int ftp_rqfcr[MAX_FILER_IDX + 1];



static inline int gfar_has_errata(struct gfar_private *priv,

				  enum gfar_errata err)

{

	return priv->errata & err;

}



static inline u32 gfar_read(volatile unsigned __iomem *addr)

{

	u32 val;