Subject: Re: [PATCH v4 6/6] hwmon: use smp_call_on_cpu() for dell-smm i8k
To: =?UTF-8?Q?Pali_Roh=c3=a1r?= <pali.rohar@gmail.com>,
        Guenter Roeck <linux@roeck-us.net>
References: <1459833007-11618-1-git-send-email-jgross@suse.com>
 <1459833007-11618-7-git-send-email-jgross@suse.com>
 <20160405145414.GB27359@roeck-us.net> <201604052131.52765@pali>
 <20160421105724.GK29406@pali>
Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org,
        boris.ostrovsky@oracle.com, david.vrabel@citrix.com, mingo@redhat.com,
        peterz@infradead.org, Douglas_Warzecha@dell.com, jdelvare@suse.com,
        tglx@linutronix.de, hpa@zytor.com, jeremy@goop.org,
        chrisw@sous-sol.org, akataria@vmware.com, rusty@rustcorp.com.au,
        virtualization@lists.linux-foundation.org, x86@kernel.org
From: Juergen Gross <jgross@suse.com>
Message-ID: <5718D1D4.3040309@suse.com>
Date: Thu, 21 Apr 2016 15:12:52 +0200
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On 21/04/16 12:57, Pali Rohár wrote:
> On Tuesday 05 April 2016 21:31:52 Pali Rohár wrote:
>> On Tuesday 05 April 2016 16:54:14 Guenter Roeck wrote:
>>> On Tue, Apr 05, 2016 at 07:10:07AM +0200, Juergen Gross wrote:
>>>> Use the smp_call_on_cpu() function to call system management
>>>> mode on cpu 0.
>>>> Make call secure by adding get_online_cpus() to avoid e.g. suspend
>>>> resume cycles in between.
>>>>
>>>> Signed-off-by: Juergen Gross <jgross@suse.com>
>>>> ---
>>>> V4: add call to get_online_cpus()
>>>
>>> Pali, any chance to test this ?
>>
>> I can test it, but just on machine where (probably) smm calls can be 
>> send from any cpu... Need some time for testing and I believe I can do 
>> that at the end of the week.
> 
> Sorry I had absolutely no more free time last weekend :-( And same
> prediction is for this weekend and also next one...

Pali, I've got a Dell laptop (Latitude E6440) here. Would this device be
okay for a test? What would you do for testing? In case you can give me
some hints how to do a sensible test I'd do it.

I've verified by adding a printk() to smp_call_on_cpu() that at least
one of the modified drivers has been used during system boot.


Juergen