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Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage

From Jon Hunter <jonathanh@nvidia.com>
Newsgroups linux.kernel
Subject Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage
Date 2015-08-24 10:50 +0200
Message-ID <q0VC2-2AJ-13@gated-at.bofh.it> (permalink)
References <pYPAJ-83V-3@gated-at.bofh.it> <pYPAJ-83V-1@gated-at.bofh.it> <q0EhP-3bT-5@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On 23/08/15 15:17, Vinod Koul wrote:
> On Tue, Aug 18, 2015 at 02:49:09PM +0100, Jon Hunter wrote:
> 
>> @@ -1543,7 +1531,7 @@ static int tegra_dma_pm_suspend(struct device *dev)
>>  	int ret;
>>  
>>  	/* Enable clock before accessing register */
>> -	ret = tegra_dma_runtime_resume(dev);
>> +	ret = pm_runtime_get_sync(dev);
> 
> why is this required ?

Because the clock could be disabled when this function is called. This
function saves the DMA context so that if the context is lost during
suspend, it can be restored.

Cheers
Jon

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Thread

Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Vinod Koul <vinod.koul@intel.com> - 2015-08-23 16:20 +0200
  Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Jon Hunter <jonathanh@nvidia.com> - 2015-08-24 10:50 +0200
    Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Vinod Koul <vinod.koul@intel.com> - 2015-08-24 11:30 +0200
      Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Jon Hunter <jonathanh@nvidia.com> - 2015-08-24 15:30 +0200
        Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Vinod Koul <vinod.koul@intel.com> - 2015-08-24 16:20 +0200
          Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage "Rafael J. Wysocki" <rjw@rjwysocki.net> - 2015-08-25 01:40 +0200
            Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Jon Hunter <jonathanh@nvidia.com> - 2015-08-25 11:40 +0200
              Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> - 2015-08-26 00:50 +0200
                Re: [RFC PATCH 1/7] DMA: tegra-apb: Correct runtime-pm usage Jon Hunter <jonathanh@nvidia.com> - 2015-08-28 12:40 +0200

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