Messages in this thread | | | Subject | Re: [PATHCv10 1/2] usb: USB Type-C connector class | From | Oliver Neukum <> | Date | Wed, 16 Nov 2016 10:39:27 +0100 |
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On Wed, 2016-11-16 at 11:30 +0200, Heikki Krogerus wrote: > On Tue, Nov 15, 2016 at 04:19:10PM -0800, Badhri Jagan Sridharan wrote:
> > Is that too costly to have ? > > Greg, could you give your opinion. In this case we do have attribute > files that the user space can poll. Data role is the USB data role, so > host or device, and it can change for example if the partner executes > a swap. The same can happen with the power role.
IMHO the uevent is cheaper. User space cannot just poll without further infrastructure. A task needs to run to poll. A uevent can be handled through established infrastructure. Sure from a kernel level it is the heavier gun, but I think this is the wrong angle of looking at this issue.
Regards Oliver
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