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 15:49:03 -0500

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.

Jon