Re: [PATCH V3 2/8] nvme: add sysfs attribute to change admin timeout per nvme controller

[Hannes Reinecke <hare@suse.de>]

On 4/23/26 14:46, Daniel Wagner wrote:
> On Wed, Apr 22, 2026 at 01:08:44PM +0200, Maurizio Lombardi wrote:
>> On Wed Apr 22, 2026 at 12:10 PM CEST, Daniel Wagner wrote:
>>> On Fri, Apr 10, 2026 at 09:39:18AM +0200, Maurizio Lombardi wrote:
>>>> +	/*
>>>> +	 * Wait until the controller reaches the LIVE state
>>>> +	 * to be sure that admin_q and fabrics_q are
>>>> +	 * properly initialized.
>>>> +	 */
>>>> +	if (!test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags))
>>>> +		return -EBUSY;
>>>
>>> I assume the idea is to use an udev rule to set the value. Though I
>>> think this is racy:
>>>
>>> 	nvme_change_uevent(ctrl, "NVME_EVENT=connected");
>>> 	set_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags);
>>
>>
>> Not really, the idea was about to prevent the user from setting the
>> timeouts too early during the controller's initialization.
> 
> Yes, but then how do you know when is too early? Do you read/poll the
> state of the controller?
> 
Well, a timeout less than KATO is questionable, as we cannot detect any
timeouts reliably until then. So having a KATO of 20 seconds with a
command timeout of 10 seconds will be pointless.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                  Kernel Storage Architect
hare@suse.de                                +49 911 74053 688
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