Messages in this thread | | | Date | Fri, 19 Aug 2022 15:38:27 +0100 | From | Mark Brown <> | Subject | Re: [PATCH v1] regmap: introduce value tracing for regmap bulk operations |
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On Fri, Aug 19, 2022 at 03:25:44PM +0100, Marc Zyngier wrote: > On 2022-08-18 16:43, Mark Brown wrote: > > On Thu, Aug 18, 2022 at 02:49:20PM +0100, Marc Zyngier wrote:
> > > I don't care much about regmap as a MMIO backend, but it strikes me as > > > odd that you end up with multiple ways of logging the same stuff (with > > > a memcpy in the middle of it).
> > > Why can't this be done with a small amount of trace post-processing?
> > At the minute we don't put the actual data for the bulk transfers into > > the trace so the information simply isn't there.
> But isn't that what this patch should do?
I'd imagine so based on a quick glance at the description, I've not actually reviewed it yet, but in that case I'm not sure what your concern is here?
> We also have recently merged the CONFIG_TRACE_MMIO_ACCESS which > already dumps all sort of MMIO crap^Winformation.
Yes, that'd also cover it for MMIO based regmaps when enabled but obviously other buses exist and can also be accessed via regmap.
> Surely there should be a more common approach to this.
There's an argument for tracing at each abstraction layer since they're generally all doing *something*, people will look to the layer they're accessing and for things like tracing register accesses with buses like I2C and SPI regmap is adding the register semantics on top of a bus that's just a byte stream. Even on buses with a native concept of an address there's stuff like paging which might be added on depending on the device. They should probably all follow a similar pattern but I'm not sure we can do everything at once. [unhandled content-type:application/pgp-signature] | |