Re: [PATCH] nvme: Fix nvme_get/set_features() with a NULL result pointer
From: Jens Axboe <axboe@fb.com>
Date: 2016-08-25 14:22:52
Also in:
linux-nvme, lkml
On 08/25/2016 01:54 AM, Andy Lutomirski wrote:
On Thu, Aug 25, 2016 at 12:38 AM, Christoph Hellwig [off-list ref] wrote:quoted
Ooops, yes. Are you looking into new nvme_set_features users? Another thing we need to tackle is either replacing dma_addr argument with a a real kernel pointer (or just kill it until users show up)I am, and I have a patch to do the former (and to add a length argument). But that's not -stable material. While I have your attention: the new use is to enable APST (power saving). In theory, it seems like I should integrate with dev_pm_qos so that the standard interface for setting a latency limit will work, but, on brief inspection, there are literally no drivers in the entire tree that do this. Am I missing something? My current draft patch just adds a sysfs attribute. (It saves a *lot* of power on my laptop, so supporting APST is worth doing.)
Care to send out what you have? I'd be interested in seeing how much I can save on my laptop, haven't played with APST yet. -- Jens Axboe