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: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h
index ac4a92e..0a0483c 100644
--- a/drivers/net/gianfar.h
+++ b/drivers/net/gianfar.h
@@ -1025,6 +1025,10 @@
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 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 @@
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;