Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value

From	Daniel Lezcano <daniel.lezcano@linaro.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH] clocksource/drivers/pistachio: Fix wrong calculated clocksource read value
Date	2015-12-15 22:00 +0100
Message-ID	<qG4Rs-MI-17@gated-at.bofh.it> (permalink)
References	<qyKuv-8c2-47@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 11/25/2015 04:42 PM, Jisheng Zhang wrote:
> Let's assume the counter value is 0xf000000, the pistachio clocksource
> 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 ?

Thanks

   -- Daniel


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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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