On 8/6/21 9:51 PM, Kent Gibson wrote: > On Fri, Aug 06, 2021 at 09:52:54PM -0700, Dipen Patel wrote: >> On 8/6/21 8:07 PM, Kent Gibson wrote: >>> On Fri, Aug 06, 2021 at 07:41:09PM -0700, Dipen Patel wrote: >>>> On 7/31/21 8:43 AM, Kent Gibson wrote: >>>>> On Wed, Jul 28, 2021 at 04:59:08PM -0700, Dipen Patel wrote: >>>>>> Thanks Kent for the review comment. My responses inline. >>>>>> > <snip> > >>>> 2. Does hte handler solution create race between two handlers? i.e. edge_irq_handler and >>>> >>>> hte_handler, for the worst case scenario as below? >>>> >>> No. If hardware timestamp is selected then no irq is requested from the >>> irq subsystem for that line - only from the hte subsystem instead. >>> So there will be no edge_irq_handler call for that line, so no possible race. >> That is not possible for certain providers, for example the one I am dealing >> >> with which requires GPIO line to be requested as input and IRQ needs to >> >> be enabled on them. >> > So, for your hte subsystem to work, the consumer has to also request > a line from the irq subsystem? Yes > That makes sense to you? Its not me, its peculiarity of the hardware that I am dealing with. > Have hte do that, rather than the consumer. Sure, for cdev it would mean to duplicate (most of) the edge* or line_create code in HTE. For such hardware, my initial doubt remains the same about the worst case scenario between two handlers, but perhaps that's implementation details for hte to handle. > > And another reason it makes sense to integrate this with irq... Alright, will explore this route as well. I remember both Thierry[1] and Marc[2] raised some doubts (time to revive that discussion). [1]: https://lore.kernel.org/lkml/YFm9r%2FtFkzVlYDEp@xxxxxxxxxxxxxxx/ [2]: https://lore.kernel.org/lkml/87h7l1k9yi.wl-maz@xxxxxxxxxx/ > > Cheers, > Kent.
