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From: Dimitris Michailidis <dm@chelsio•com>
To: Stephen Hemminger <shemminger@linux-foundation•org>
Cc: Casey Leedom <leedom@chelsio•com>,
	Ben Hutchings <bhutchings@solarflare•com>,
	David Miller <davem@davemloft•net>,
	netdev@vger•kernel.org
Subject: Re: [PATCH net-next] cxgb4: don't hold RTNL during ethtool phys_id
Date: Thu, 07 Apr 2011 01:18:51 -0700	[thread overview]
Message-ID: <4D9D736B.3050106@chelsio.com> (raw)
In-Reply-To: <20110406173308.4737e9d4@nehalam>

Stephen Hemminger wrote:
> On Wed, 6 Apr 2011 17:20:29 -0700
> Casey Leedom <leedom@chelsio•com> wrote:
> 
>> | From: Stephen Hemminger <shemminger@linux-foundation•org>
>> | Date: Wednesday, April 06, 2011 05:09 pm
>> | 
>> | The Chelsio cxgb4 drivers implement blinking in a unique way by
>> | waiting on the mailbox. This patch cleans it up slightly by no longer
>> | holding the system wide network configuration lock during the process.
>> | 
>> | The patch also uses correct semantics for the time argument
>> | which is supposed to be in seconds; and zero is supposed
>> | to signify infinite blinking.
>> | 
>> | This is still a bad firmware interface design for this
>> | since it means the board is basically hung while doing the blink.
>> | But fixing it correctly would require hardware and firmware
>> | documentation. With that information the device could be converted
>> | to the new set_phys_id.
>> | 
>> | Compile tested only.
>> | 
>> | Signed-off-by: Stephen Hemminger <shemminger@vyatta•com>
>>
>>   Are you assuming that the firmware won't respond with a command completion 
>> until the LED blinking is complete?  If so, that's a bad assumption.  The 
>> firmware runs as an asynchronous real-time OS.  The LED blinking simply becomes 
>> a thread of activity within the OS and the command completes immediately.
>>
>> Casey
> 
> Then how is LED blinking stopped?

You can pass 0 as blinks to cancel your request, which may or may not cancel 
the LED blinking depending on what other drivers have concurrent blinking 
requests in progress.  But you can't pass UINT_MAX as the patch does.  I'll 
fix it up to use the new ethtool interface this week.

  reply	other threads:[~2011-04-07  8:19 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-04-07  0:09 [PATCH net-next] cxgb4: don't hold RTNL during ethtool phys_id Stephen Hemminger
2011-04-07  0:20 ` Casey Leedom
2011-04-07  0:33   ` Stephen Hemminger
2011-04-07  8:18     ` Dimitris Michailidis [this message]
2011-04-07  0:35   ` Ben Hutchings

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