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Groups > linux.kernel > #1292797
| From | Jisheng Zhang <jszhang@marvell.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value |
| Date | 2015-12-16 08:40 +0100 |
| Message-ID | <qGeQN-7gA-5@gated-at.bofh.it> (permalink) |
| References | <qyKuv-8c2-47@gated-at.bofh.it> <qG4Rs-MI-17@gated-at.bofh.it> <qGexr-78d-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Wed, 16 Dec 2015 15:11:25 +0800
Jisheng Zhang wrote:
> Dear Daniel,
>
> On Tue, 15 Dec 2015 21:59:30 +0100 Daniel Lezcano wrote:
>
> > On 11/25/2015 04:42 PM, Jisheng Zhang wrote:
> > > Let's assume the counter value is 0xf000000, the pistachio clocksource
oops, sorry, should be 0xf0000000. Do I need to send a v2 patch?
> > > read cycles function would return 0xffffffff0fffffff, but it should
> > > return 0xfffffff.
> > >
> > > We fix this issue by calculating bitwise-not counter, then cast to
> > > cycle_t.
> > >
> > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> >
> > Hi Jisheng,
> >
> > I tried to reproduce this behavior on x86_64 but without success.
> >
> > On which architecture did you produce this result ? Do you have a simple
> > test program to check with ?
>
> I have no HW platforms with pistachio, just read the code and run the
> following test code in x86_64 and x86_32:
>
> #include <stdio.h>
> unsigned long long pistachio_clocksource_read_cycles()
> {
> unsigned int counter = 0xf000000;
should be unsigned int counter = 0xf0000000;
> return ~(unsigned long long)counter;
> }
> int main()
> {
> printf("%llx\n", pistachio_clocksource_read_cycles());
> return 0;
> }
>
> Thanks,
> Jisheng
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-12-15 22:00 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Jisheng Zhang <jszhang@marvell.com> - 2015-12-16 08:20 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Jisheng Zhang <jszhang@marvell.com> - 2015-12-16 08:40 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Jisheng Zhang <jszhang@marvell.com> - 2015-12-16 08:50 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Jisheng Zhang <jszhang@marvell.com> - 2015-12-16 09:00 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-12-16 10:30 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-12-16 10:40 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Russell King - ARM Linux <linux@arm.linux.org.uk> - 2015-12-16 11:40 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-12-16 17:30 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Jisheng Zhang <jszhang@marvell.com> - 2015-12-17 10:20 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-12-16 11:40 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-12-16 10:10 +0100
Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value Daniel Lezcano <daniel.lezcano@linaro.org> - 2015-12-16 10:10 +0100
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