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From: anurupvasu@gmail.com (Anurup M)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v6 08/11] drivers: perf: hisi: use poll method to avoid L3C counter overflow
Date: Mon, 27 Mar 2017 12:03:24 +0530	[thread overview]
Message-ID: <58D8B234.3020004@gmail.com> (raw)
In-Reply-To: <20170324114325.GC22771@leverpostej>



On Friday 24 March 2017 05:13 PM, Mark Rutland wrote:
>>> How do we ensure that we don't take the interrupt in the middle of a
>>> > >sequence of accesses to the HW?
>> >
>> >The L3 cache and MN PMU does not use the overflow IRQ and it does
>> >not occur here
>> >as the interrupt Mask register is by default masked in hardware.
> I was referring to the timer interrupt which backs the hrtimer.
>
> i.e. how do we guarantee that hisi_hrtimer_callback() is not called
> while we are in the middle of a RMW sequence? Are interrupts disabled
> for all of those seqeunces?

The HW access via djtag read and write are protected by spin_lock_irqsave.

Thanks,
Anurup

> Thanks,
> Mark.

  reply	other threads:[~2017-03-27  6:33 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-10  6:28 [PATCH v6 08/11] drivers: perf: hisi: use poll method to avoid L3C counter overflow Anurup M
2017-03-21 17:16 ` Mark Rutland
2017-03-24  6:43   ` Anurup M
2017-03-24 11:43     ` Mark Rutland
2017-03-27  6:33       ` Anurup M [this message]
2017-03-28 11:09         ` Mark Rutland

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