From: Sergei Shtylyov <sshtylyov@ru.mvista.com>
To: Jon Smirl <jonsmirl@gmail.com>
Cc: linuxppc-dev <Linuxppc-dev@ozlabs.org>
Subject: Re: solution to printk() blocking interrupts?
Date: Mon, 22 Sep 2008 14:03:26 +0400 [thread overview]
Message-ID: <48D76D6E.2020002@ru.mvista.com> (raw)
In-Reply-To: <9e4733910809211634u5b37e297pe8503f08de4f19a8@mail.gmail.com>
Hello.
Jon Smirl wrote:
>> Implementing the poll_controller() method in the network driver is usually
>> staightforward.
>>
>
> Good tip, the simple implementation worked.
>
> What controls this? "carrier detect appears untrustworthy, waiting 4 seconds"
>
IIRC, it happens if netpoll code sees the carrier OK right ast the
first time it checks it. Look for this message in net/core/netpoll.c...
> Get that fixed and this patch could be useful,
>
How that hinders using netconsole?
> root@phyCORE-MPC5200B-tiny:~ dmesg | grep netconsole
> Kernel command line: console=ttyPSC0,115200 rw debug root=/dev/nfs
> ip=dhcp nfsroot=192.168.1.4:/home/OSELAS.BSP-Phytec-phyCORE-MPC5200B-tiny-6/root,v3,tcp
> netconsole=6666@192.168.1.11/eth0,514@192.168.1.4/00:19:d1:e4:0f:8d
> netconsole: local port 6666
> netconsole: local IP 192.168.1.11
> netconsole: interface eth0
> netconsole: remote port 514
> netconsole: remote IP 192.168.1.4
> netconsole: remote ethernet address 00:19:d1:e4:0f:8d
> netconsole: device eth0 not up yet, forcing it
> netconsole: carrier detect appears untrustworthy, waiting 4 seconds
> netconsole: network logging started
> root@phyCORE-MPC5200B-tiny:~
>
>
>
> diff --git a/drivers/net/fec_mpc52xx.c b/drivers/net/fec_mpc52xx.c
> index 4e4f683..72541b5 100644
> --- a/drivers/net/fec_mpc52xx.c
> +++ b/drivers/net/fec_mpc52xx.c
> @@ -401,6 +401,16 @@ static int mpc52xx_fec_hard_start_xmit(struct
> sk_buff *skb, struct net_device *d
> return 0;
> }
>
> +#ifdef CONFIG_NET_POLL_CONTROLLER
> +static void mpc52xx_fec_poll_controller(struct net_device *dev)
> +{
> + disable_irq(dev->irq);
> + mpc52xx_fec_tx_interrupt(dev->irq, dev);
>
The interrupt nu,ber seems wrong, although the handler doesn't care
anyway...
> + enable_irq(dev->irq);
> +}
> +#endif
>
Hey, how about the Rx interrupt? And I'm seeing
mcp52xx_fec_interrupt() on separate IRQ too -- looks like for for this
driver this is not as straightforward as it usually is.
You need to call all the handlers -- netconsole is not the only user of
the netpoll API, so not only Tx should be handled.
WBR, Sergei
next prev parent reply other threads:[~2008-09-22 10:03 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-21 20:53 solution to printk() blocking interrupts? Jon Smirl
2008-09-21 21:43 ` Jon Smirl
2008-09-21 22:21 ` Sergei Shtylyov
2008-09-21 23:34 ` Jon Smirl
2008-09-22 5:17 ` Benjamin Herrenschmidt
2008-09-22 11:04 ` Sergei Shtylyov
2008-09-22 11:11 ` Sergei Shtylyov
2008-09-22 14:39 ` Sergei Shtylyov
2008-09-22 14:45 ` Jon Smirl
2008-09-22 14:59 ` Sergei Shtylyov
2008-09-22 21:27 ` Benjamin Herrenschmidt
2008-09-22 10:03 ` Sergei Shtylyov [this message]
2008-09-22 11:01 ` Sergei Shtylyov
2008-09-22 11:21 ` Sergei Shtylyov
2008-09-22 13:45 ` Jon Smirl
2008-09-23 5:46 ` Benjamin Herrenschmidt
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