Messages in this thread | ![/](/images/icornerl.gif) | | From | Sergey Shtylyov <> | Subject | Re: [PATCH net-next v2 20/21] net: ravb: Do not apply RX CSUM settings to hardware if the interface is down | Date | Thu, 21 Dec 2023 21:50:06 +0300 |
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On 12/17/23 5:34 PM, claudiu beznea wrote:
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>>> From: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> >>> >>> Do not apply the RX CSUM settings to hardware if the interface is down. In >>> case runtime PM is enabled, and while the interface is down, the IP will be >>> in reset mode (as for some platforms disabling/enabling the clocks will >>> switch the IP to standby mode, which will lead to losing registers' >> >> To/From perhaps? >> And just "register". >> >>> content) and applying settings in reset mode is not an option. Instead, >>> cache the RX CSUM settings and apply them in ravb_open(). >> >> Have this issue actually occurred for you? > > Setting RX CSUM while the if is down? No. > >>> Commit prepares for the addition of runtime PM. >>> >>> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com> >> [...] >> >>> diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c >>> index 633346b6cd7c..9ff943dff522 100644 >>> --- a/drivers/net/ethernet/renesas/ravb_main.c >>> +++ b/drivers/net/ethernet/renesas/ravb_main.c >>> @@ -1868,6 +1868,15 @@ static int ravb_open(struct net_device *ndev) >>> if (info->gptp || info->ccc_gac) >>> ravb_ptp_init(ndev, priv->pdev); >>> >>> + /* Apply features that might have been changed while the interface >>> + * was down. >>> + */ >>> + if (ndev->hw_features & NETIF_F_RXCSUM) { >> >> I'm afraid this is a wrong field; we need ndev->features, no? > > RX CSUM is not enabled for all ravb aware devices (see struct > ravb_hw_info::net_hw_features). We should be setting the ECMR only for > these ones. ravb_hw_info::net_hw_features is set in ndev->hw_features in > probe(). So here code checks if platforms supports RXCSUM and then below it > applies what has been requested though ndo_set_features(), if any.
OK. But we don't need this snippet here anyway...
>>> + u32 val = (ndev->features & NETIF_F_RXCSUM) ? ECMR_RCSC : 0; >>> + >>> + ravb_modify(ndev, ECMR, ECMR_RCSC, val); >>> + } >>> + >> >> The ECMR setting is already done in ravb_emac_init_rcar(), no need >> to duplicate it here, I think... > > Ok, it worth being moved there.
No need to move, it's already there...
[...] >>> @@ -2337,6 +2346,9 @@ static void ravb_set_rx_csum(struct net_device *ndev, bool enable) >>> struct ravb_private *priv = netdev_priv(ndev); >>> unsigned long flags; >>> >>> + if (!netif_running(ndev)) >> >> Racy as well... > > It's also called with rtnl_mutex locked.
Well, at least the only place that calls the ndo_set_features() method, __netdev_update_features() calls ASSERT_RTNL() at the start. However, since we'd have to use the is_opened flag anyway, let's rely on it instead...
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MBR, Sergey
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