[PATCH] NVMe: Increase shutdown complete time

[Dan McLeran]

CAP.TO is defined as the worst case time the driver should wait for the 
controller to come ready. Not sure it can be used for shutdown as well. If 
so, then we should just read that value and use it as we do in 
nvme_wait_ready.

On Mon, 31 Mar 2014, Robles, Raymond C wrote:

> You're probably fine waiting anywhere up to CAP.TO.
>
> -----Original Message-----
> From: Linux-nvme [mailto:linux-nvme-bounces at lists.infradead.org] On Behalf Of Dan McLeran
> Sent: Monday, March 31, 2014 11:57 AM
> To: Busch, Keith
> Cc: linux-nvme at lists.infradead.org
> Subject: Re: [PATCH] NVMe: Increase shutdown complete time
>
> Seems reasonable to me.
>
> On Mon, 31 Mar 2014, Keith Busch wrote:
>
>> The spec doesn't have a recommendation for shutdown beyond "that the
>> host wait a minimum of one second for the shutdown operations to
>> complete", so we need to choose an arbitrarily value so we don't wait
>> forever but high enough to prevent unsafe shutdowns. Some h/w vendors
>> say the previous two seconds is not long enough at some capacities.
>> Twenty seconds ought to be enough for anybody, right?
>>
>> Signed-off-by: Keith Busch <keith.busch at intel.com>
>> ---
>> drivers/block/nvme-core.c |    2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/block/nvme-core.c b/drivers/block/nvme-core.c
>> index 625259d..103da93 100644
>> --- a/drivers/block/nvme-core.c
>> +++ b/drivers/block/nvme-core.c
>> @@ -1352,7 +1352,7 @@ static int nvme_shutdown_ctrl(struct nvme_dev *dev)
>> 	cc = (readl(&dev->bar->cc) & ~NVME_CC_SHN_MASK) | NVME_CC_SHN_NORMAL;
>> 	writel(cc, &dev->bar->cc);
>>
>> -	timeout = 2 * HZ + jiffies;
>> +	timeout = 20 * HZ + jiffies;
>> 	while ((readl(&dev->bar->csts) & NVME_CSTS_SHST_MASK) !=
>> 							NVME_CSTS_SHST_CMPLT) {
>> 		msleep(100);
>> --
>> 1.7.10.4
>>
>>
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>>
>
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