From: Shawn Guo <shawnguo@kernel.org>
To: Kohji Okuno <okuno.kohji@jp.panasonic.com>
Cc: Fabio Estevam <fabio.estevam@nxp.com>,
Sascha Hauer <s.hauer@pengutronix.de>,
Pengutronix Kernel Team <kernel@pengutronix.de>,
linux-arm-kernel@lists.infradead.org,
NXP Linux Team <linux-imx@nxp.com>
Subject: Re: [PATCH v3] ARM: imx6q: cpuidle: fix bug that CPU might not wake up at expected time
Date: Mon, 4 Mar 2019 15:06:58 +0800 [thread overview]
Message-ID: <20190304070656.GF26041@dragon> (raw)
In-Reply-To: <20190226023413.19531-1-okuno.kohji@jp.panasonic.com>
On Tue, Feb 26, 2019 at 11:34:13AM +0900, Kohji Okuno wrote:
> In the current cpuidle implementation for i.MX6q, the CPU that sets
> 'WAIT_UNCLOCKED' and the CPU that returns to 'WAIT_CLOCKED' are always
> the same. While the CPU that sets 'WAIT_UNCLOCKED' is in IDLE state of
> "WAIT", if the other CPU wakes up and enters IDLE state of "WFI"
> istead of "WAIT", this CPU can not wake up at expired time.
> Because, in the case of "WFI", the CPU must be waked up by the local
> timer interrupt. But, while 'WAIT_UNCLOCKED' is set, the local timer
> is stopped, when all CPUs execute "wfi" instruction. As a result, the
> local timer interrupt is not fired.
> In this situation, this CPU will wake up by IRQ different from local
> timer. (e.g. broacast tiemr)
s/tiemr/timer
>
> So, this fix changes CPU to return to 'WAIT_CLOCKED'.
>
> Signed-off-by: Kohji Okuno <okuno.kohji@jp.panasonic.com>
Applied the patch with following Fixes tag.
Fixes: e5f9dec8ff5f ("ARM: imx6q: support WAIT mode using cpuidle")
Thanks for the fixing.
Shawn
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next prev parent reply other threads:[~2019-03-04 7:08 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-22 8:49 [PATCH] ARM: imx6q: cpuidle: fix bug that CPU may not wake up Kohji Okuno
2019-02-22 9:14 ` Lucas Stach
2019-02-22 12:25 ` Fabio Estevam
2019-02-26 2:06 ` [PATCH v2] ARM: imx6q: cpuidle: fix bug that CPU might not wake up at expected time Kohji Okuno
2019-02-26 2:12 ` Fabio Estevam
2019-02-26 2:19 ` Kohji Okuno
2019-02-26 2:22 ` Fabio Estevam
2019-02-26 2:23 ` Kohji Okuno
2019-02-26 2:34 ` [PATCH v3] " Kohji Okuno
2019-03-01 9:23 ` Shawn Guo
2019-03-04 1:28 ` Kohji Okuno
2019-03-04 7:00 ` Shawn Guo
2019-03-04 7:06 ` Shawn Guo [this message]
2019-03-04 7:38 ` Kohji Okuno
2019-03-05 10:38 ` Kohji Okuno
2019-03-06 3:21 ` Shawn Guo
2019-03-06 4:30 ` [PATCH] ARM: imx6: cpuidle: omit the unnecessary unmask of GINT Kohji Okuno
2019-03-19 12:51 ` Shawn Guo
2019-03-20 0:07 ` Kohji Okuno
2019-03-20 1:12 ` Peng Fan
2019-03-20 3:08 ` Aisheng Dong
2019-03-20 7:44 ` Shawn Guo
2019-03-20 7:59 ` Peng Fan
2019-03-20 14:28 ` Shawn Guo
2019-03-20 14:35 ` Shawn Guo
2019-03-06 14:36 ` [PATCH v3] ARM: imx6q: cpuidle: fix bug that CPU might not wake up at expected time Peng Fan
2019-03-07 0:06 ` Kohji Okuno
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