Messages in this thread | | | From | <> | Subject | Re: [PATCH 4/5] net: macb: WoL support for GEM type of Ethernet controller | Date | Tue, 21 Apr 2020 08:21:48 +0000 |
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On 17/04/2020 at 19:14, Nicolas Ferre wrote: > On 16/04/2020 at 19:44, nicolas.ferre@microchip.com wrote: >> From: Nicolas Ferre <nicolas.ferre@microchip.com> >> >> Adapt the Wake-on-Lan feature to the Cadence GEM Ethernet controller. >> This controller has different register layout and cannot be handled by >> previous code. >> We disable completely interrupts on all the queues but the queue 0. >> Handling of WoL interrupt is done in another interrupt handler >> positioned depending on the controller version used, just between >> suspend() and resume() calls. >> It allows to lower pressure on the generic interrupt hot path by >> removing the need to handle 2 tests for each IRQ: the first figuring out >> the controller revision, the second for actually knowing if the WoL bit >> is set. >> >> Queue management in suspend()/resume() functions inspired from RFC patch >> by Harini Katakam <harinik@xilinx.com>, thanks! >> >> Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com> >> --- >> drivers/net/ethernet/cadence/macb.h | 3 + >> drivers/net/ethernet/cadence/macb_main.c | 121 ++++++++++++++++++++--- >> 2 files changed, 109 insertions(+), 15 deletions(-) > > [..] > >> @@ -4534,23 +4564,56 @@ static int __maybe_unused macb_suspend(struct device *dev) >> struct macb_queue *queue = bp->queues; >> unsigned long flags; >> unsigned int q; >> + int err; >> >> if (!netif_running(netdev)) >> return 0; >> >> if (bp->wol & MACB_WOL_ENABLED) { >> - macb_writel(bp, IER, MACB_BIT(WOL)); >> - macb_writel(bp, WOL, MACB_BIT(MAG)); >> - enable_irq_wake(bp->queues[0].irq); >> - netif_device_detach(netdev); >> - } else { >> - netif_device_detach(netdev); >> + spin_lock_irqsave(&bp->lock, flags); >> + /* Flush all status bits */ >> + macb_writel(bp, TSR, -1); >> + macb_writel(bp, RSR, -1); >> for (q = 0, queue = bp->queues; q < bp->num_queues; >> - ++q, ++queue) >> - napi_disable(&queue->napi); >> - rtnl_lock(); >> - phylink_stop(bp->phylink); >> - rtnl_unlock(); >> + ++q, ++queue) { >> + /* Disable all interrupts */ >> + queue_writel(queue, IDR, -1); >> + queue_readl(queue, ISR); >> + if (bp->caps & MACB_CAPS_ISR_CLEAR_ON_WRITE) >> + queue_writel(queue, ISR, -1); >> + } >> + /* Change interrupt handler and >> + * Enable WoL IRQ on queue 0 >> + */ >> + if (macb_is_gem(bp)) { >> + devm_free_irq(dev, bp->queues[0].irq, bp->queues); >> + err = devm_request_irq(dev, bp->queues[0].irq, gem_wol_interrupt, >> + IRQF_SHARED, netdev->name, bp->queues); >> + if (err) { >> + dev_err(dev, >> + "Unable to request IRQ %d (error %d)\n", >> + bp->queues[0].irq, err); >> + return err; >> + } >> + queue_writel(bp->queues, IER, GEM_BIT(WOL)); >> + gem_writel(bp, WOL, MACB_BIT(MAG)); >> + } else { >> + queue_writel(bp->queues, IER, MACB_BIT(WOL)); >> + macb_writel(bp, WOL, MACB_BIT(MAG)); >> + } >> + spin_unlock_irqrestore(&bp->lock, flags); >> + >> + enable_irq_wake(bp->queues[0].irq); >> + } >> + >> + netif_device_detach(netdev); >> + for (q = 0, queue = bp->queues; q < bp->num_queues; >> + ++q, ++queue) >> + napi_disable(&queue->napi); >> + >> + if (!(bp->wol & MACB_WOL_ENABLED)) { >> + phy_stop(netdev->phydev); >> + phy_suspend(netdev->phydev); > > Bug here: you must read: > > rtnl_lock(); > phylink_stop(bp->phylink); > rtnl_unlock(); > > Instead of the 2 previous lines. I'll correct in v2. > > Sorry for the regression. > > >> spin_lock_irqsave(&bp->lock, flags); >> macb_reset_hw(bp); >> spin_unlock_irqrestore(&bp->lock, flags); >> @@ -4575,20 +4638,48 @@ static int __maybe_unused macb_resume(struct device *dev) > > [..] > BTW: I have issue having a real resume event from the phy with this > series. I'm investigating that but didn't find anything for now. > > Observation #1: when the WoL is not enabled, I don't have link issue. > But the path in suspend/resume is far more intrusive in phy state. > > Observation #2: when WoL is enabled, I need to do a full ifdown/ifup > sequence for gain access again to the link: > > ip link show eth0 > 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast > state DOWN mode DEFAULT group default qlen 1000 > link/ether 54:10:ec:be:50:b0 brd ff:ff:ff:ff:ff:ff > > ifdown eth0 && ifup eth0 > > ip link show eth0 > 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast > state UP mode DEFAULT group default qlen 1000 > link/ether 54:10:ec:be:50:b0 brd ff:ff:ff:ff:ff:ff > > Observation #3: I didn't experience this behavior while playing with the > WoL on my 4.19 kernel before porting to Mainline.
I've reviewed this series to fix this last issues. It's was a combination of runtime_pm not handled properly and a mix of netif_carrier_* call with phylink calls not well positioned nor balanced between suspend and resume.
I have a v2 series that I'm preparing for today: Harini, I prefer to post it now so it could avoid that you hit the same issues as me while testing on your platform.
Best regards, Nicolas
-- Nicolas Ferre
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