Subject: [PATCH v3 04/12] Serial: OMAP: Add runtime pm support for omap-serial driver

From: [email-masked] (Jon Hunter)
Date: Thu, 9 Jun 2011 15:51:14 -0500

On 06/09/2011 03:49 PM, Jon Hunter wrote:
> Hi Govindraj
>
> On 06/08/2011 11:35 PM, Govindraj wrote:
>> On Thu, Jun 9, 2011 at 2:09 AM, Jon Hunter<[email-masked]> wrote:
>>> Hi Govindraj,
>>>
>>> On 6/8/2011 6:23 AM, Govindraj.R wrote:
>>>
>>> [snip]
>>>
>>>> +
>>>> +#define OMAP_UART_AUTOSUSPEND_DELAY (30 * HZ) /* Value is msecs */
>>>
>>> [snip]
>>>
>>>> @@ -1295,18 +1381,36 @@ static int serial_omap_probe(struct
>>>> platform_device *pdev)
>>>> up->uart_dma.rx_dma_channel = OMAP_UART_DMA_CH_FREE;
>>>> }
>>>>
>>>> + pm_runtime_use_autosuspend(&pdev->dev);
>>>> + pm_runtime_set_autosuspend_delay(&pdev->dev,
>>>> + OMAP_UART_AUTOSUSPEND_DELAY);
>>>
>>> Something is weird here...DEFAULT_AUTOSUSPEND_DELAY is defined as
>>> (30*HZ)
>>> which would appear to be jiffies (ticks per second) and NOT msecs.
>>> However,
>>> pm_runtime_set_autosuspend is clearly expecting msecs. So this seems to
>>> conflict. By default 30*HZ for omap would be 30*128 = 3840ms so not
>>> quite 4
>>> seconds.
>>>
>>> What were you intending here?
>>
>> Intention is to get approx 3 secs timeout for autosuspend.
>
> In that case you should just define DEFAULT_AUTOSUSPEND_DELAY as 30000.
> The above is just confusing as you are mixing time types and hence, it
> is not clear what you intend the default timeout to be.

Sorry, I meant 3000 and not 30000 above, if you want 3 secs.

Jon