linux-kernel - Re: [PATCH V2] dma: tegra: enable/disable dma clock

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Message-ID: <500E2BE0.7060602@nvidia.com>
Date:	Tue, 24 Jul 2012 10:30:16 +0530
From:	Laxman Dewangan <ldewangan@...dia.com>
To:	Vinod Koul <vinod.koul@...ux.intel.com>
CC:	"dan.j.williams@...el.com" <dan.j.williams@...el.com>,
	Stephen Warren <swarren@...dia.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH V2] dma: tegra: enable/disable dma clock

On Tuesday 24 July 2012 10:38 AM, Vinod Koul wrote:
> On Fri, 2012-07-20 at 13:31 +0530, Laxman Dewangan wrote:
>> Enable the DMA clock when allocating channel and
>> disable clock when freeing channels.
>>
>> Signed-off-by: Laxman Dewangan<ldewangan@...dia.com>
>> ---
>> +	clk_disable_unprepare(tdma->dma_clk);
> What if another channel is active, disabling clock can cause bad
> behavior. You should check here if all channels are idle and then
> disable, or is this handled by clock API?

Yes, clock driver keeps the reference count and so client driver need 
not to take care.

Thanks,
Laxman


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