[Vivid/Utopic][SRU][PATCH] UBUNTU: SAUCE: rtsx_usb_ms: Use msleep_interruptible() in polling loop

[Chris J Arges]

On 01/21/2015 01:17 PM, Chris J Arges wrote:
> 
> 
> On 01/21/2015 09:40 AM, Andy Whitcroft wrote:
>> On Wed, Jan 21, 2015 at 09:24:00AM -0600, Chris J Arges wrote:
>>> From: Ben Hutchings <ben at decadent.org.uk>
>>>
>>> BugLink: http://bugs.launchpad.net/bugs/1413149
>>>
>>> rtsx_usb_ms creates a task that mostly sleeps, but tasks in
>>> uninterruptible sleep still contribute to the load average (for
>>> bug-compatibility with Unix).  A load average of ~1 on a system that
>>> should be idle is somewhat alarming.
>>>
>>> Change the sleep to be interruptible, but still ignore signals.
>>>
>>> A better fix might be to replace this loop with a delayed work item.
>>>
>>> References: https://bugs.debian.org/765717
>>> Signed-off-by: Ben Hutchings <ben at decadent.org.uk>
>>> Signed-off-by: Chris J Arges <chris.j.arges at canonical.com>
>>> ---
>>>  drivers/memstick/host/rtsx_usb_ms.c | 3 ++-
>>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/memstick/host/rtsx_usb_ms.c b/drivers/memstick/host/rtsx_usb_ms.c
>>> index a7282b7..7356780 100644
>>> --- a/drivers/memstick/host/rtsx_usb_ms.c
>>> +++ b/drivers/memstick/host/rtsx_usb_ms.c
>>> @@ -706,7 +706,8 @@ poll_again:
>>>  		if (host->eject)
>>>  			break;
>>>  
>>> -		msleep(1000);
>>> +		if (msleep_interruptible(1000))
>>> +			flush_signals(current);
>>>  	}
>>>  
>>>  	complete(&host->detect_ms_exit);
>>
>> While this looks perfectly reasonable and comes from a trustworthy
>> source, is this making its way upstream?
>>
>> -apw
>>
> 
> Yes, this was posted upstream last November, but no response was
> received yet.
> --chris
> 

Just a few more data points:
- This has already been applied to Debian's 3.16 kernel
- The reporter has already tested this patch applied to an Ubuntu kernel
and it has fixed their issue

--chris