Re: clk: Per controller locks (prepare & enable)

From	Javier Martinez Canillas <javier@osg.samsung.com>
Newsgroups	linux.kernel
Subject	Re: clk: Per controller locks (prepare & enable)
Date	2016-07-05 16:00 +0200
Message-ID	<rRz3k-3vi-17@gated-at.bofh.it> (permalink)
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Hello Krzysztof,

On 07/05/2016 02:33 AM, Krzysztof Kozlowski wrote:
> On 07/04/2016 05:15 PM, Javier Martinez Canillas wrote:

[snip]

>>
>> Yes, splitting the lock per controller will fix the possible deadlock in
>> this case but I think we need an approach that is safe for all possible
>> scenarios. Otherwise it will work more by coincidence than due a design.
> 
> This is not a coincidence. This design is meant to fix this deadlock.
> Not by coincidence. By design.
>

Ok, if the configurations I described doesn't exist in practice and are
just theoretical then yes, doing a per controller lock is a good design. 
 
> You are talking about theoretical different configurations... without
> even real bug reports. I am providing an idea to fix a real deadlock and
> your argument is that it might not fix other (non-reported) deadlocks.
> These other deadlocks happen now as well probably...
>

I'm not against you re-working the locks to do it per controller, is just
that I thought it would be good to have a solution that is going to work
for all possible scenarios.

You asked for comments/opinions/ideas and I gave mine, that's all :)

> Best regards,
> Krzysztof
> 

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America

Thread

clk: Per controller locks (prepare & enable) Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2016-06-29 09:30 +0200
  Re: clk: Per controller locks (prepare & enable) Javier Martinez Canillas <javier@osg.samsung.com> - 2016-06-30 18:30 +0200
    Re: clk: Per controller locks (prepare & enable) Javier Martinez Canillas <javier@osg.samsung.com> - 2016-07-04 17:20 +0200
      Re: clk: Per controller locks (prepare & enable) Javier Martinez Canillas <javier@osg.samsung.com> - 2016-07-04 17:30 +0200
      Re: clk: Per controller locks (prepare & enable) Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2016-07-05 08:40 +0200
        Re: clk: Per controller locks (prepare & enable) Javier Martinez Canillas <javier@osg.samsung.com> - 2016-07-05 16:00 +0200
          Re: clk: Per controller locks (prepare & enable) Charles Keepax <ckeepax@opensource.wolfsonmicro.com> - 2016-07-07 14:10 +0200
            Re: clk: Per controller locks (prepare & enable) Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2016-07-07 14:50 +0200
              Re: clk: Per controller locks (prepare & enable) Charles Keepax <ckeepax@opensource.wolfsonmicro.com> - 2016-07-07 18:10 +0200
    Re: clk: Per controller locks (prepare & enable) Krzysztof Kozlowski <k.kozlowski@samsung.com> - 2016-07-04 10:30 +0200

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