Hi Thomas,

On Mon, Aug 25, 2014 at 10:52:51AM +0200, Thomas Poussevin wrote:

Hi,
I noticed that with touchscreen drivers that don't explicitly call a
input_sync after input_register_device, suspend to ram is blocked if
no event is sent, because the input_dev created is considered as not
synchronized. The problem was seen with Atmel mxt driver. When any
event is sent, the driver explicitly ask a sync, so the problem is
solved.
The problem occurs only when the screen has never send any event
before suspend to ram.
I solved it setting the sync element to true (when input dev is
created, no element is pending).
Is there a better way to solve the problem ?

It is not clear to me what the problem is. The kernel as far as I
remember never checked state of 'sync' field when executing suspend
callbacks. Moreover there is no longer 'sync' field at all in mainline.

It sounds like some userspace code makes assumptions that are not always
valid.

Thanks.

-- 
Dmitry