From: Nikita Yushchenko <nikita.yo...@cogentembedded.com> Sent: Friday, November 25, 2016 6:02 PM >To: Andy Duan <fugang.d...@nxp.com>; David S. Miller ><da...@davemloft.net>; Troy Kisky <troy.ki...@boundarydevices.com>; >Andrew Lunn <and...@lunn.ch>; Eric Nelson <e...@nelint.com>; Philippe >Reynes <trem...@gmail.com>; Johannes Berg <johan...@sipsolutions.net>; >net...@vger.kernel.org; linux-kernel@vger.kernel.org >Cc: Chris Healy <cphe...@gmail.com>; Nikita Yushchenko ><nikita.yo...@cogentembedded.com> >Subject: [PATCH] net: fec: turn on device when extracting statistics > >Execution 'ethtool -S' on fec device that is down causes OOPS on Vybrid >board: > >Unhandled fault: external abort on non-linefetch (0x1008) at 0xe0898200 pgd >= ddecc000 [e0898200] *pgd=9e406811, *pte=400d1653, *ppte=400d1453 >Internal error: : 1008 [#1] SMP ARM ... > >Reason of OOPS is that fec_enet_get_ethtool_stats() accesses fec registers >while IPG clock is stopped by PM. > >Fix that by wrapping statistics extraction into pm_runtime_get_sync() ... >pm_runtime_put_autosuspend() braces. > >Signed-off-by: Nikita Yushchenko <nikita.yo...@cogentembedded.com> >---
Acked-by: Fugang Duan <fugang.d...@nxp.com> > drivers/net/ethernet/freescale/fec_main.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > >diff --git a/drivers/net/ethernet/freescale/fec_main.c >b/drivers/net/ethernet/freescale/fec_main.c >index 5aa9d4ded214..9c7592b80ce8 100644 >--- a/drivers/net/ethernet/freescale/fec_main.c >+++ b/drivers/net/ethernet/freescale/fec_main.c >@@ -2317,10 +2317,19 @@ static void fec_enet_get_ethtool_stats(struct >net_device *dev, > struct ethtool_stats *stats, u64 *data) { > struct fec_enet_private *fep = netdev_priv(dev); >- int i; >+ int i, ret; >+ >+ ret = pm_runtime_get_sync(&fep->pdev->dev); >+ if (IS_ERR_VALUE(ret)) { >+ memset(data, 0, sizeof(*data) * ARRAY_SIZE(fec_stats)); >+ return; >+ } > > for (i = 0; i < ARRAY_SIZE(fec_stats); i++) > data[i] = readl(fep->hwp + fec_stats[i].offset); >+ >+ pm_runtime_mark_last_busy(&fep->pdev->dev); >+ pm_runtime_put_autosuspend(&fep->pdev->dev); > } > > static void fec_enet_get_strings(struct net_device *netdev, >-- >2.1.4