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Re: [PATCH v2 5/6] hpet: removing unused variable m in hpet_interrupt

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Corentin Labbe wrote:
> This patch fix the following warning:
> drivers/char/hpet.c:146:17: attention : variable ‘m’ set but not used [-Wunused-but-set-variable]
> by removing the unused variable m in hpet_interrupt

This patch might silence the warning, but it leaves the bug that
actually caused the warning.

As far as I can see, the computation of "base" should use "m".

But the entire algorithm is completely bogus because it does not
actually remove the race condition; the counter is likely to have
advanced beyond the "mc" value when the new comparator value is
written.  Also see arch/x86/kernel/hpet.c for how hpet_next_event()
handles this.

And why a non-periodic timer should generate periodic interrupts is
another question.

And nobody uses this crap.
So I'm really not sure what to do about this ...


Regards,
Clemens

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[PATCH v2 0/6] hpet: fix build warnings and style Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200
  [PATCH v2 1/6] hpet: remove unused variable hpet in hpet_ioctl_common Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200
  [PATCH v2 5/6] hpet: removing unused variable m in hpet_interrupt Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200
    Re: [PATCH v2 5/6] hpet: removing unused variable m in hpet_interrupt Clemens Ladisch <clemens@ladisch.de> - 2017-04-03 15:10 +0200
      Re: [PATCH 1/2] Alps HID I2C T4 device support Nikolaus Rath <Nikolaus@rath.org> - 2017-04-04 05:10 +0200
        RE: [PATCH 1/2] Alps HID I2C T4 device support Masaki Ota <masaki.ota@jp.alps.com> - 2017-04-04 09:00 +0200
          RE: [PATCH 1/2] Alps HID I2C T4 device support Masaki Ota <masaki.ota@jp.alps.com> - 2017-04-05 01:50 +0200
            Re: [PATCH 1/2] Alps HID I2C T4 device support Nikolaus Rath <Nikolaus@rath.org> - 2017-04-05 01:50 +0200
              RE: [PATCH 1/2] Alps HID I2C T4 device support Masaki Ota <masaki.ota@jp.alps.com> - 2017-04-05 01:50 +0200
                Re: [PATCH 1/2] Alps HID I2C T4 device support Nikolaus Rath <Nikolaus@rath.org> - 2017-04-05 02:10 +0200
                RE: [PATCH 1/2] Alps HID I2C T4 device support Masaki Ota <masaki.ota@jp.alps.com> - 2017-04-05 10:50 +0200
                Re: [PATCH 1/2] Alps HID I2C T4 device support Nikolaus Rath <Nikolaus@rath.org> - 2017-04-05 20:40 +0200
                RE: [PATCH 1/2] Alps HID I2C T4 device support Masaki Ota <masaki.ota@jp.alps.com> - 2017-04-06 03:10 +0200
                Re: [PATCH 1/2] Alps HID I2C T4 device support Nikolaus Rath <Nikolaus@rath.org> - 2017-04-07 01:10 +0200
  [PATCH v2 2/6] hpet: remove unused writeq/readq function definitions Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200
  [PATCH v2 6/6] hpet: fix style issue about braces and alignment Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200
    Re: [PATCH v2 6/6] hpet: fix style issue about braces and alignment Joe Perches <joe@perches.com> - 2017-04-04 05:50 +0200
  [PATCH v2 4/6] hpet: replace printk by their pr_xxx counterparts Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200
    Re: [PATCH v2 4/6] hpet: replace printk by their pr_xxx counterparts Joe Perches <joe@perches.com> - 2017-04-03 21:50 +0200
  [PATCH v2 3/6] hpet: fix checkpatch complains about spaces Corentin Labbe <clabbe.montjoie@gmail.com> - 2017-04-03 14:20 +0200

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