From mboxrd@z Thu Jan  1 00:00:00 1970
From: james.morse@arm.com (James Morse)
Date: Wed, 17 Jan 2018 12:01:08 +0000
Subject: [PATCH v6 11/16] firmware: arm_sdei: Add support for CPU and
 system power states
In-Reply-To: <20180114122037.GA18073@red-moon>
References: <20180108153818.22743-1-james.morse@arm.com>
 <20180108153818.22743-12-james.morse@arm.com>
 <20180108172226.GC2530@red-moon>
 <20180113120031.5m6eykwzqnioyb33@armageddon.cambridge.arm.com>
 <20180114122037.GA18073@red-moon>
Message-ID: <5A5F3B04.6070403@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi Lorenzo, Catalin,

On 14/01/18 12:20, Lorenzo Pieralisi wrote:
> On Sat, Jan 13, 2018 at 12:00:31PM +0000, Catalin Marinas wrote:
>> On Mon, Jan 08, 2018 at 05:22:26PM +0000, Lorenzo Pieralisi wrote:
>>> On Mon, Jan 08, 2018 at 03:38:13PM +0000, James Morse wrote:
>>>> +/* When entering idle, mask/unmask events for this cpu */
>>>
>>> Just mentioning (since I know you know), this notifier is called also
>>> through syscore_ops so it is not just idle (CPUidle or Suspend-to-idle).
>>>
>>>> +static int sdei_pm_notifier(struct notifier_block *nb, unsigned long action,
>>>> +			    void *data)
>>>> +{
>>>> +	int rv;
>>>> +
>>>> +	switch (action) {
>>>> +	case CPU_PM_ENTER:
>>>> +		rv = sdei_mask_local_cpu();
>>>> +		break;
>>>> +	case CPU_PM_EXIT:
>>>> +		rv = sdei_unmask_local_cpu();
>>>
>>> You should handle CPU_PM_ENTER_FAILED here for correctness,
>>> in case the notifier chain fails.

(not seen this before, I mirrored what KVM does here ... which may have the same
bug)


>> So, just to confirm, the CPU_PM_ENTER_FAILED case goes together with
>> CPU_PM_EXIT so that we unmask the SDE again for the CPU.
> 
> Yes, that's correct (I do not think that's a problem with current
> mainline but that ought to be handled correctly anyway).

I'll send a fix..,
... oh wait Catalin already did this.


Thanks!

James