On Fri, Aug 06, 2021 at 10:35:10PM -0700, 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. My point is that the peculiarities of the hardware should be hidden from the hte API user, especially if it is only necessary for some hardware. > > 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. And your current way every other hte user will have to duplicate the gpiolib-cdev code.... > 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. > Indeed. Cheers, Kent. > > > > 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.
