On Sat, Dec 16, 2017 at 2:51 AM, Brian King brking@linux.vnet.ibm.com wrote:

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.

Thanks for the patch. We need more time to review.

Cc: stable stable@vger.kernel.org Signed-off-by: Brian King brking@linux.vnet.ibm.com

---

drivers/net/ethernet/broadcom/tg3.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index de51c21..d09c5a9 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -14225,7 +14225,9 @@ 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);
  

-- 1.8.3.1