Messages in this thread | | | Subject | Re: [PATCH] clocksource/drivers/tango-xtal: Replace code by clocksource_mmio_init | From | Marc Gonzalez <> | Date | Tue, 17 Nov 2015 13:48:46 +0100 |
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On 17/11/2015 13:22, Daniel Lezcano wrote: > On 11/13/2015 01:20 PM, Marc Gonzalez wrote: >> On 13/11/2015 11:58, Daniel Lezcano wrote: >> >>> The current code to initialize, register and read the clocksource is >>> already factored out in mmio.c via the clocksource_mmio_init function. >>> >>> Factor out the code with the clocksource_mmio_init function. >> >> The reason I didn't like clocksource_mmio_init() is because it exports >> 4 generic accessors. >> >> I guess this function makes more sense when all platforms are using it, >> in an ARCH_MULTIPLATFORM kernel. (Also the accessors are probably quite >> small, so the waste is probably minimal.) > > Hi Marc, > > it is not clear for me if you agree with this patch or not. Can you > clarify ?
[ Adding rmk as the original mmio.c author ]
Hello Daniel,
It's hard to give a straight answer. From my limited perspective (building a kernel for Sigma boards only) I feel that mmio.c brings nothing. (As you mentioned, it would be interesting to measure whether having reg_base in the ctx, rather than as a global is better or worse for perf, though the actual difference may be lost in the noise.)
On the other hand, I can see how a different perspective, such as yours, may see benefits in having all drivers use the same APIs; and there may be other savings for ARCH_MULTIPLATFORM builds with lots of platforms.
I guess if you think it is a good patch, I will defer to your experience.
I just wish Thomas would take a look at my mmio patch. I will make an official submission, so that it can be properly shot down :-)
Regards.
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