From 511d934f4496076898e45aaa09e0c85376eb16ee Mon Sep 17 00:00:00 2001 From: Anton Vorontsov Date: Wed, 30 Jun 2010 06:39:15 +0000 Subject: [PATCH] gianfar: Implement workaround for eTSEC-A002 erratum MPC8313ECE says: "If the controller receives a 1- or 2-byte frame (such as an illegal runt packet or a packet with RX_ER asserted) before GRS is asserted and does not receive any other frames, the controller may fail to set GRSC even when the receive logic is completely idle. Any subsequent receive frame that is larger than two bytes will reset the state so the graceful stop can complete. A MAC receiver (Rx) reset will also reset the state." This patch implements the proposed workaround: "If IEVENT[GRSC] is still not set after the timeout, read the eTSEC register at offset 0xD1C. If bits 7-14 are the same as bits 23-30, the eTSEC Rx is assumed to be idle and the Rx can be safely reset. If the register fields are not equal, wait for another timeout period and check again." Signed-off-by: Anton Vorontsov Signed-off-by: David S. Miller --- drivers/net/gianfar.c | 40 +++++++++++++++++++++++++++++++++++++--- drivers/net/gianfar.h | 1 + 2 files changed, 38 insertions(+), 3 deletions(-) diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c index c2fabc1853ad..fccb7a371cc8 100644 --- a/drivers/net/gianfar.c +++ b/drivers/net/gianfar.c @@ -947,6 +947,11 @@ static void gfar_detect_errata(struct gfar_private *priv) (pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0)) priv->errata |= GFAR_ERRATA_76; + /* MPC8313 and MPC837x all rev */ + if ((pvr == 0x80850010 && mod == 0x80b0) || + (pvr == 0x80861010 && (mod & 0xfff9) == 0x80c0)) + priv->errata |= GFAR_ERRATA_A002; + if (priv->errata) dev_info(dev, "enabled errata workarounds, flags: 0x%x\n", priv->errata); @@ -1570,6 +1575,29 @@ static void init_registers(struct net_device *dev) gfar_write(®s->minflr, MINFLR_INIT_SETTINGS); } +static int __gfar_is_rx_idle(struct gfar_private *priv) +{ + u32 res; + + /* + * Normaly TSEC should not hang on GRS commands, so we should + * actually wait for IEVENT_GRSC flag. + */ + if (likely(!gfar_has_errata(priv, GFAR_ERRATA_A002))) + return 0; + + /* + * Read the eTSEC register at offset 0xD1C. If bits 7-14 are + * the same as bits 23-30, the eTSEC Rx is assumed to be idle + * and the Rx can be safely reset. + */ + res = gfar_read((void __iomem *)priv->gfargrp[0].regs + 0xd1c); + res &= 0x7f807f80; + if ((res & 0xffff) == (res >> 16)) + return 1; + + return 0; +} /* Halt the receive and transmit queues */ static void gfar_halt_nodisable(struct net_device *dev) @@ -1593,12 +1621,18 @@ static void gfar_halt_nodisable(struct net_device *dev) tempval = gfar_read(®s->dmactrl); if ((tempval & (DMACTRL_GRS | DMACTRL_GTS)) != (DMACTRL_GRS | DMACTRL_GTS)) { + int ret; + tempval |= (DMACTRL_GRS | DMACTRL_GTS); gfar_write(®s->dmactrl, tempval); - spin_event_timeout(((gfar_read(®s->ievent) & - (IEVENT_GRSC | IEVENT_GTSC)) == - (IEVENT_GRSC | IEVENT_GTSC)), -1, 0); + do { + ret = spin_event_timeout(((gfar_read(®s->ievent) & + (IEVENT_GRSC | IEVENT_GTSC)) == + (IEVENT_GRSC | IEVENT_GTSC)), 1000000, 0); + if (!ret && !(gfar_read(®s->ievent) & IEVENT_GRSC)) + ret = __gfar_is_rx_idle(priv); + } while (!ret); } } diff --git a/drivers/net/gianfar.h b/drivers/net/gianfar.h index c414374f407f..710810e2adb4 100644 --- a/drivers/net/gianfar.h +++ b/drivers/net/gianfar.h @@ -1028,6 +1028,7 @@ struct gfar_priv_grp { enum gfar_errata { GFAR_ERRATA_74 = 0x01, GFAR_ERRATA_76 = 0x02, + GFAR_ERRATA_A002 = 0x04, }; /* Struct stolen almost completely (and shamelessly) from the FCC enet source -- 2.30.2