lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Thu, 9 May 2019 22:54:04 +0200 From: "Rafael J. Wysocki" <rafael@...nel.org> To: Keith Busch <kbusch@...nel.org> Cc: Mario Limonciello <Mario.Limonciello@...l.com>, Kai-Heng Feng <kai.heng.feng@...onical.com>, Christoph Hellwig <hch@....de>, Jens Axboe <axboe@...com>, Sagi Grimberg <sagi@...mberg.me>, "Rafael J. Wysocki" <rafael@...nel.org>, Linux PM <linux-pm@...r.kernel.org>, Rafael Wysocki <rafael.j.wysocki@...el.com>, Linux Kernel Mailing List <linux-kernel@...r.kernel.org>, linux-nvme <linux-nvme@...ts.infradead.org>, Keith Busch <keith.busch@...el.com> Subject: Re: [PATCH] nvme-pci: Use non-operational power state instead of D3 on Suspend-to-Idle On Thu, May 9, 2019 at 9:33 PM Keith Busch <kbusch@...nel.org> wrote: > > On Thu, May 09, 2019 at 06:57:34PM +0000, Mario.Limonciello@...l.com wrote: > > No, current Windows versions don't transition to D3 with inbox NVME driver. > > You're correct, it's explicit state transitions even if APST was enabled > > (as this patch is currently doing as well). > > The proposed patch does too much, and your resume latency will be worse > off for doing an unnecessary controller reset. > > The following should be all that's needed if the device is spec > compliant. The resume part isn't necessary if npss is non-operational, but > we're not saving that info, and it shouldn't hurt to be explicit anyway. > > I don't have any PS capable devices, so this is just compile tested. > > --- > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c > index 6265d9225ec8..ce8b9bc949b9 100644 > --- a/drivers/nvme/host/core.c > +++ b/drivers/nvme/host/core.c > @@ -1132,6 +1132,22 @@ static int nvme_set_features(struct nvme_ctrl *dev, unsigned fid, unsigned dword > return ret; > } > > +int nvme_set_power(struct nvme_ctrl *ctrl, unsigned npss) > +{ > + int ret; > + > + mutex_lock(&ctrl->scan_lock); > + nvme_start_freeze(ctrl); > + nvme_wait_freeze(ctrl); > + ret = nvme_set_features(ctrl, NVME_FEAT_POWER_MGMT, npss, NULL, 0, > + NULL); > + nvme_unfreeze(ctrl); > + mutex_unlock(&ctrl->scan_lock); > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(nvme_set_power); > + > int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count) > { > u32 q_count = (*count - 1) | ((*count - 1) << 16); > diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h > index 527d64545023..f2be6aad9804 100644 > --- a/drivers/nvme/host/nvme.h > +++ b/drivers/nvme/host/nvme.h > @@ -459,6 +459,7 @@ int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd, > unsigned timeout, int qid, int at_head, > blk_mq_req_flags_t flags, bool poll); > int nvme_set_queue_count(struct nvme_ctrl *ctrl, int *count); > +int nvme_set_power(struct nvme_ctrl *ctrl, unsigned npss); > void nvme_stop_keep_alive(struct nvme_ctrl *ctrl); > int nvme_reset_ctrl(struct nvme_ctrl *ctrl); > int nvme_reset_ctrl_sync(struct nvme_ctrl *ctrl); > diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c > index a90cf5d63aac..2c4154cb4e79 100644 > --- a/drivers/nvme/host/pci.c > +++ b/drivers/nvme/host/pci.c > @@ -18,6 +18,7 @@ > #include <linux/mutex.h> > #include <linux/once.h> > #include <linux/pci.h> > +#include <linux/suspend.h> > #include <linux/t10-pi.h> > #include <linux/types.h> > #include <linux/io-64-nonatomic-lo-hi.h> > @@ -2851,6 +2852,8 @@ static int nvme_suspend(struct device *dev) > struct pci_dev *pdev = to_pci_dev(dev); > struct nvme_dev *ndev = pci_get_drvdata(pdev); > > + if (!pm_suspend_via_firmware()) > + return nvme_set_power(&ndev->ctrl, ndev->ctrl.npss); You probably want to call pci_save_state(pdev) in the branch above to prevent pci_pm_suspend_noirq() from calling pci_prepare_to_sleep() going forward, so I would write this routine as if (pm_suspend_via_firmware()) { nvme_dev_disable(ndev, true); return 0; } pci_save_state(pdev) return nvme_set_power(&ndev->ctrl, ndev->ctrl.npss); > nvme_dev_disable(ndev, true); > return 0; > } > @@ -2860,6 +2863,8 @@ static int nvme_resume(struct device *dev) > struct pci_dev *pdev = to_pci_dev(dev); > struct nvme_dev *ndev = pci_get_drvdata(pdev); > > + if (!pm_suspend_via_firmware()) > + return nvme_set_power(&ndev->ctrl, 0); > nvme_reset_ctrl(&ndev->ctrl); > return 0; > } The rest of the patch LGTM.
Powered by blists - more mailing lists