On 8/6/21 10:35 PM, Dipen Patel wrote: > 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. Ignore code duplicate comment, shouldn't be big deal. > 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.
