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gianfar: Implement workaround for eTSEC74 erratum

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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: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Anton Vorontsov 2010-06-30 06:39:12 +00:00 committed by David S. Miller
parent 70777d0346
commit 7d3509774c
2 changed files with 38 additions and 2 deletions
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29
drivers/net/gianfar.c
View File

@ -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);

11
drivers/net/gianfar.h
View File

@ -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;