From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Lina Iyer <lina.iyer@linaro.org>
Cc: ulf.hansson@linaro.org, khilman@linaro.org,
linux-pm@vger.kernel.org, Mark Rutland <mark.rutland@arm.com>,
k.kozlowski@samsung.com,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
sboyd@codeaurora.org, rjw@rjwysocki.net, msivasub@codeaurora.org,
geert@linux-m68k.org, agross@codeaurora.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 7/7] ARM: smp: Add runtime PM support for CPU hotplug
Date: Fri, 4 Sep 2015 10:17:35 +0100 [thread overview]
Message-ID: <20150904091735.GC21084@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <1441310314-8857-8-git-send-email-lina.iyer@linaro.org>
On Thu, Sep 03, 2015 at 01:58:34PM -0600, Lina Iyer wrote:
> @@ -401,6 +412,11 @@ asmlinkage void secondary_start_kernel(void)
> local_irq_enable();
> local_fiq_enable();
>
> + /* We are running, enable runtime PM for the CPU. */
> + cpu_dev = get_cpu_device(cpu);
> + if (cpu_dev)
> + pm_runtime_get_sync(cpu_dev);
> +
Please no. This is fragile.
pm_runtime_get_sync() can sleep, and this path is used when the system
is fully up and running. Locks may be held, which cause this to sleep.
However, we're calling it from a context where we can't sleep - which
is the general rule for any part of system initialisation where we
have not entered the idle thread yet (the idle thread is what we run
when sleeping.)
NAK on this.
--
FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up
according to speedtest.net.
next prev parent reply other threads:[~2015-09-04 9:17 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-03 19:58 [PATCH v2 0/7] PM / Domains: Generic PM domains for CPUs/Clusters Lina Iyer
2015-09-03 19:58 ` [PATCH v2 1/7] PM / Domains: Allocate memory outside domain locks Lina Iyer
2015-09-03 19:58 ` [PATCH v2 2/7] PM / Domains: Support IRQ safe PM domains Lina Iyer
2015-09-04 10:02 ` Ulf Hansson
2015-09-04 16:05 ` Lina Iyer
2015-10-01 21:11 ` Geert Uytterhoeven
2015-09-03 19:58 ` [PATCH v2 3/7] drivers: cpu: Define CPU devices as IRQ safe Lina Iyer
2015-09-04 4:00 ` Stephen Boyd
2015-09-03 19:58 ` [PATCH v2 4/7] PM / Domains: Introduce PM domains for CPUs/clusters Lina Iyer
2015-09-04 3:54 ` Stephen Boyd
2015-09-03 19:58 ` [PATCH v2 5/7] ARM: cpuidle: Add runtime PM support for CPU idle Lina Iyer
2015-09-03 19:58 ` [PATCH v2 6/7] ARM64: smp: Add runtime PM support for CPU hotplug Lina Iyer
2015-09-30 12:36 ` Geert Uytterhoeven
2015-09-03 19:58 ` [PATCH v2 7/7] ARM: " Lina Iyer
2015-09-04 3:59 ` Stephen Boyd
2015-09-04 15:13 ` Lina Iyer
2015-09-04 7:39 ` Geert Uytterhoeven
2015-09-04 9:17 ` Russell King - ARM Linux [this message]
2015-09-04 9:27 ` Russell King - ARM Linux
2015-09-04 15:12 ` Lina Iyer
2015-09-04 16:23 ` Russell King - ARM Linux
2015-09-04 17:02 ` Lina Iyer
2015-09-04 17:46 ` Russell King - ARM Linux
2015-09-04 17:57 ` Grygorii Strashko
2015-09-04 18:45 ` Alan Stern
2015-09-04 21:46 ` Grygorii Strashko
2015-09-05 15:39 ` Alan Stern
2015-09-07 13:04 ` Rafael J. Wysocki
2015-09-07 13:37 ` Grygorii Strashko
2015-09-07 20:42 ` Rafael J. Wysocki
2015-09-08 8:21 ` Grygorii Strashko
2015-09-08 22:03 ` Kevin Hilman
2015-09-10 11:01 ` Grygorii Strashko
2015-09-22 17:32 ` Lina Iyer
2015-09-22 20:53 ` Thomas Gleixner
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