tg3: Fix rx hang on MTU change with 5717/5719

[ Upstream commit 748a240c589824e9121befb1cba5341c319885bc ]

This fixes a hang issue seen when changing the MTU size from 1500 MTU
to 9000 MTU on both 5717 and 5719 chips. In discussion with Broadcom,
they've indicated that these chipsets have the same phy as the 57766
chipset, so the same workarounds apply. This has been tested by IBM
on both Power 8 and Power 9 systems as well as by Broadcom on x86
hardware and has been confirmed to resolve the hang issue.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 3613469dc5c61c33f4a82e297fc7383583582a76..ab53e0cfb4dca4c4473ced94d0e0a1808dc37bb1 100644 (file)
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -14228,7 +14228,9 @@ static int tg3_change_mtu(struct net_device *dev, int new_mtu)
        /* Reset PHY, otherwise the read DMA engine will be in a mode that
         * breaks all requests to 256 bytes.
         */
-       if (tg3_asic_rev(tp) == ASIC_REV_57766)
+       if (tg3_asic_rev(tp) == ASIC_REV_57766 ||
+           tg3_asic_rev(tp) == ASIC_REV_5717 ||
+           tg3_asic_rev(tp) == ASIC_REV_5719)
                reset_phy = true;
 
        err = tg3_restart_hw(tp, reset_phy);