2013/11/4 Jonas Jensen <jonas.jensen@xxxxxxxxx>: > Thanks for the replies. > > On 1 November 2013 18:01, Florian Fainelli <florian@xxxxxxxxxxx> wrote: >>> + dev_err(&bus->dev, "%s timed out\n", __func__); >> >> I would keep these as a debugging aid and not spawn error messages on >> the console by default. > > Done. > > >>> + snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(&pdev->dev)); >> >> If you only support device tree probing, this might be fine, but you >> might want to be safe in case someone does a !OF instantiation and >> also use pdev->id as an additional unique identifier, so something >> like: >> >> %s-%d-mii, pdev->name, pdev->id >> >> will work. > > Done. > > >>> + /* Setting PHY_IGNORE_INTERRUPT here even if it has no effect, >>> + * of_mdiobus_register() sets these PHY_POLL. >>> + * Ideally, the interrupt from MAC controller could be used to >>> + * detect link state changes, not polling, i.e. if there was >>> + * a way phy_driver could set PHY_HAS_INTERRUPT but have that >>> + * interrupt handled in ethernet drivercode. >>> + */ >>> + for (i = 0; i < PHY_MAX_ADDR; i++) >>> + bus->irq[i] = PHY_IGNORE_INTERRUPT; >> >> This type of configuration where the PHY interrupt is actually >> serviced by a link interrupt bit in the Ethernet MAC driver now works >> since 5ea94e768 ("phy: add phy_mac_interrupt() to use with >> PHY_IGNORE_INTERRUPT") so setting PHY_IGNORE_INTERRUPT is the right >> way to signal this and this will no longer make the PHY library poll >> for the link state. > > Yes, I tried using phy_mac_interrupt() but had some difficulties (I'll > explain below). It seemed to be what I want and is wrapped with > EXPORT_SYMBOL(). > > However, as of next-20131104 I don't see how this works for DT probed > devices (those that set PHY_IGNORE_INTERRUPT). > > As I tried to explain in my comment, of_mdiobus_register() assigns > PHY_POLL to the IRQ array: > > drivers/of/of_mdio.c > .. > int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np) > { > .. > /* Clear all the IRQ properties */ > if (mdio->irq) > for (i=0; i<PHY_MAX_ADDR; i++) > mdio->irq[i] = PHY_POLL; You are right, I missed that part. We can't really assign a dedicated interrupt line for your PHY, so we need another way of dealing with these PHY interrupts present at the Ethernet MAC level. [snip] > This is why I ended up setting PHY_IGNORE_INTERRUPT and the comment > about its effectiveness. Polling works but the extra reads on the bus > seem unnecessary. > Ideas how they can be eliminated are appreciated. As of today, the only way to work around it is not to use of_mdiobus_register() and use mdiobus_register() directly which will allow you to properly describe such a configuration. > > > Another problem, when phy_mac_interrupt() is called from NAPI it looks > like it's trying to take a lock it already has. I tried moving it out > of poll, placing it directly in IRQ handler, with the same result: > > [ 18.230000] moxart-ethernet 90900000.mac eth0: moxart_poll: PHYSTS_CHG > [ 18.240000] > [ 18.240000] ================================= > [ 18.240000] [ INFO: inconsistent lock state ] > [ 18.240000] 3.12.0-rc7-next-20131104+ #1067 Not tainted > [ 18.240000] --------------------------------- > [ 18.240000] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. > [ 18.240000] kworker/0:1/123 [HC0[0]:SC0[0]:HE1:SE1] takes: > [ 18.240000] ((&dev->phy_queue)){+.?...}, at: [<c0028c08>] > process_one_work+0x13c/0x430 > [ 18.240000] {IN-SOFTIRQ-W} state was registered at: > [ 18.240000] [<c0055648>] mark_lock+0x144/0x670 > [ 18.240000] [<c005777c>] __lock_acquire+0x5e4/0x1c24 > [ 18.240000] [<c00592cc>] lock_acquire+0x6c/0x80 > [ 18.240000] [<c002a024>] flush_work+0x44/0x278 > [ 18.240000] [<c002a2e0>] __cancel_work_timer+0x88/0x124 > [ 18.240000] [<c002a390>] cancel_work_sync+0x14/0x18 > [ 18.240000] [<c01b0190>] phy_mac_interrupt+0x20/0x40 > [ 18.240000] [<c01b3450>] moxart_poll+0x2b4/0x4b4 > [ 18.240000] [<c01fe3c8>] net_rx_action+0x130/0x22c > [ 18.240000] [<c00174cc>] __do_softirq+0xe8/0x238 > [ 18.240000] [<c0017a2c>] irq_exit+0xac/0xfc > [ 18.240000] [<c0009b40>] handle_IRQ+0x3c/0x8c > [ 18.240000] [<c0008534>] handle_irq+0x98/0xa8 > [ 18.240000] [<c000c478>] __irq_svc+0x38/0x68 > [ 18.240000] [<c00487ec>] rcu_idle_exit+0x78/0xdc > [ 18.240000] [<c0040618>] cpu_startup_entry+0x88/0x130 > [ 18.240000] [<c026d3c8>] rest_init+0xb8/0xe0 > [ 18.240000] [<c033ea1c>] start_kernel+0x298/0x2dc > [ 18.240000] irq event stamp: 2659 > [ 18.240000] hardirqs last enabled at (2659): [<c0276298>] > _raw_spin_unlock_irq+0x2c/0x60 > [ 18.240000] hardirqs last disabled at (2658): [<c02760f0>] > _raw_spin_lock_irq+0x28/0x78 > [ 18.240000] softirqs last enabled at (2654): [<c0017568>] > __do_softirq+0x184/0x238 > [ 18.240000] softirqs last disabled at (2637): [<c0017a2c>] irq_exit+0xac/0xfc > [ 18.240000] > [ 18.240000] other info that might help us debug this: > [ 18.240000] Possible unsafe locking scenario: > [ 18.240000] > [ 18.240000] CPU0 > [ 18.240000] ---- > [ 18.240000] lock([ 18.240000] moxart-ethernet 90900000.mac > eth0: TX ring end reached > [ 18.240000] (&dev->phy_queue)); > [ 18.240000] <Interrupt> > [ 18.240000] lock((&dev->phy_queue)); > [ 18.240000] > [ 18.240000] *** DEADLOCK *** > [ 18.240000] > [ 18.240000] 1 lock held by kworker/0:1/123: > [ 18.240000] #0: (events){.+.+..}, at: [<c0028c08>] > process_one_work+0x13c/0x430 > [ 18.240000] > [ 18.240000] stack backtrace: > [ 18.240000] CPU: 0 PID: 123 Comm: kworker/0:1 Not tainted > 3.12.0-rc7-next-20131104+ #1067 > [ 18.240000] Workqueue: events phy_change > [ 18.240000] [<c000d214>] (unwind_backtrace+0x0/0xf4) from > [<c000b964>] (show_stack+0x18/0x1c) > [ 18.240000] [<c000b964>] (show_stack+0x18/0x1c) from [<c0271614>] > (dump_stack+0x20/0x28) > [ 18.240000] [<c0271614>] (dump_stack+0x20/0x28) from [<c026fee0>] > (print_usage_bug.part.26+0x220/0x288) > [ 18.240000] [<c026fee0>] (print_usage_bug.part.26+0x220/0x288) from > [<c0055b3c>] (mark_lock+0x638/0x670) > [ 18.240000] [<c0055b3c>] (mark_lock+0x638/0x670) from [<c00577c4>] > (__lock_acquire+0x62c/0x1c24) > [ 18.240000] [<c00577c4>] (__lock_acquire+0x62c/0x1c24) from > [<c00592cc>] (lock_acquire+0x6c/0x80) > [ 18.240000] [<c00592cc>] (lock_acquire+0x6c/0x80) from [<c0028c70>] > (process_one_work+0x1a4/0x430) > [ 18.240000] [<c0028c70>] (process_one_work+0x1a4/0x430) from > [<c0029304>] (worker_thread+0x13c/0x3dc) > [ 18.240000] [<c0029304>] (worker_thread+0x13c/0x3dc) from > [<c002f500>] (kthread+0xb8/0xd4) > [ 18.240000] [<c002f500>] (kthread+0xb8/0xd4) from [<c0009360>] > (ret_from_fork+0x14/0x34) > [ 18.610000] libphy: phy_change Ok, I will take a look into this, I realize that I was calling this from a workqueue which won't show the locking problem, thanks for the report. > > >>> + ret = of_mdiobus_register(bus, np); >>> + if (ret < 0) >>> + return ret; >> >> You still need to call mdiobus_free() here in case registration fails. > > Done. > > >>> +/* RTL8201CP */ >>> +static struct phy_driver rtl8201cp_driver = { >>> + .phy_id = 0x00008201, >>> + .name = "RTL8201CP Ethernet", >>> + .phy_id_mask = 0x0000ffff, >>> + .features = PHY_BASIC_FEATURES, >> >> If this PHY is internal to your SoC (same die/package) you should also >> add PHY_IS_INTERNAL to get a consistent ethtool reporting (among >> others). > > I was wondering about that, and now I'm sure it should not be set, the > physical chip is separate, as can be seen here: > > https://lh4.googleusercontent.com/-A-2FXDrObU8/UMcMc_K2vEI/AAAAAAAABwg/ldaLZ7ps1P4/w1331-h998-no/UC-7112-LX-picture4.jpg Right, then make that a separate patch instead. -- Florian -- Florian -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html