Hi, Greg KH wrote: > On Mon, Apr 20, 2009 at 11:54:04PM +0200, Rafael J. Wysocki wrote: > >> On Thursday 16 April 2009, Michael Trimarchi wrote: >> >>> Drivers on embedded systems would be smart enough >>> to know that some of the devices should remain powered up, because >>> they could still be useful even when the CPU wasn't running. >>> The patch add the in_use attribute, that it can be used by the >>> the drivers to avoid power down during suspend. >>> >> OK, so the idea is that in_use will be set by the user space for devices that >> shouldn't be suspended. Is this correct? >> > > If so, why? Why would you suspend anything then? Why not just have > userspace suspend the devices it wants to suspend and leave the ones it > thinks is "in_use" alone? > > Because it the previus thread the idea is that the driver should use this flag " [RFC Disable suspend on a specific device] This is a little change in linux power scheme". >> Assuming it is, I'd call the flag 'in_use' rather than 'is_inuse'. Also, if >> may_inuse is supposed to mean that we can set in_use for this device, I'd call >> it 'in_use_valid', I'd make it be unset by default and I'd allow the driver to >> unset it if it is going to react to 'in_use'. >> >> >>> Signed-off-by: Michael Trimarchi <trimarchi@xxxxxxxxxxxxxxxx> >>> Cc: "Alan Stern" <stern@xxxxxxxxxxxxxxxxxxx> >>> Cc: "Rafael J. Wysocki" <rjw@xxxxxxx> >>> Cc: "Pavel Mackek" <pavel@xxxxxx> >>> Cc: "Len Brown" <lenb@xxxxxxxxxx> >>> >>> --- >>> diff --git a/drivers/base/core.c b/drivers/base/core.c >>> index e73c92d..d67043b 100644 >>> --- a/drivers/base/core.c >>> +++ b/drivers/base/core.c >>> @@ -1124,6 +1124,49 @@ static struct device *next_device(struct klist_iter *i) >>> } >>> >>> /** >>> + * device_visit_subtree - device subtree iterator. >>> + * @root: root struct device. >>> + * @data: data for the callback. >>> + * @fn: function to be called for each device. >>> + * >>> + * Iterate the @parent's subtree devices, and call @fn for each, >>> + * passing it @data. >>> + * >>> + */ >>> >> Hmm, I'm not sure ig Greg is going to like it. >> > > I have the same big question you do: > > >> Besides, I'm not sure if it's really necessary. What's wrong with using >> simply device_for_each_child() instead? >> > > Exactly, what are you trying to do that differs from > device_for_each_child()? > Is device for each child use to visist the first level of the tree? > >>> @@ -1207,6 +1250,7 @@ int __init devices_init(void) >>> return -ENOMEM; >>> } >>> >>> +EXPORT_SYMBOL_GPL(device_visit_subtree); >>> > > I see you didn't run your patch through scripts/checkpatch.pl :) > I run the checkpatch but I find that the exported symbol are there so I add the new one. > Please do so in the future. > > thanks, > > greg k-h > > Michael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
