netdev - Re: [PATCH net 3/3] r8169: increase the lifespan of the hardware counters dump area.

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Date:	Mon, 7 Sep 2015 23:52:51 +0200
From:	Francois Romieu <romieu@...zoreil.com>
To:	Corinna Vinschen <vinschen@...hat.com>
Cc:	netdev@...r.kernel.org, David Miller <davem@...emloft.net>,
	pomidorabelisima@...il.com
Subject: Re: [PATCH net 3/3] r8169: increase the lifespan of the hardware
 counters dump area.

Corinna Vinschen <vinschen@...hat.com> :
[...]
> I have a bit of a problem with this patch.  It crashes when loading the
> driver manually w/ modprobe.  For some reason dev_get_stats is called
> during rtl_init_one and at that time the counters pointer is NULL, so
> the kernel gets a SEGV.
>
>  After I worked around that I got a SEGV in
> rtl_remove_one, which I still have to find out why.  I didn't test with
> the latest kernel, though, so I still have to check if that's the reason
> for the crashes.  That takes a bit longer, I just wanted to let you
> know.

Call me stupid: I forgot that it's perfectly fine to request the stats
of a down interface. :o/

Updated patch is on the way.

> There's also a problem with rtl8169_cmd_counters:  It always calls
> rtl_udelay_loop_wait_low w/ rtl_reset_counters_cond, even when called
> from rtl8169_update_counters, where it should call
> rtl_udelay_loop_wait_low w/ rtl_counters_cond to check for the
> CounterDump flag, rather than for the CounterReset flag.
> 
> For now I applied the below patch, but I think it's a bit ugly to
> conditionalize the rtl_cond struct by the incoming flag value.

<captain obvious>

Let's check both at once:

	return RTL_R32(CounterAddrLow) & (CounterDump | CounterReset);

</captain obvious>

Thanks for reviewing.

-- 
Ueimor
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