From e5ad96f388b765fe6b52f64f37e910c0ba4f3de7 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Tue, 27 Jul 2021 09:40:44 -0700 Subject: [PATCH] nvme-pci: disable hmb on idle suspend An idle suspend may or may not disable host memory access from devices placed in low power mode. Either way, it should always be safe to disable the host memory buffer prior to entering the low power mode, and this should also always be faster than a full device shutdown. Signed-off-by: Keith Busch Reviewed-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- drivers/nvme/host/pci.c | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 909dadcdab09..5b23d5818f75 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -3087,8 +3087,13 @@ static int nvme_resume(struct device *dev) if (ndev->last_ps == U32_MAX || nvme_set_power_state(ctrl, ndev->last_ps) != 0) - return nvme_try_sched_reset(&ndev->ctrl); + goto reset; + if (ctrl->hmpre && nvme_setup_host_mem(ndev)) + goto reset; + return 0; +reset: + return nvme_try_sched_reset(ctrl); } static int nvme_suspend(struct device *dev) @@ -3112,15 +3117,9 @@ static int nvme_suspend(struct device *dev) * the PCI bus layer to put it into D3 in order to take the PCIe link * down, so as to allow the platform to achieve its minimum low-power * state (which may not be possible if the link is up). - * - * If a host memory buffer is enabled, shut down the device as the NVMe - * specification allows the device to access the host memory buffer in - * host DRAM from all power states, but hosts will fail access to DRAM - * during S3. */ if (pm_suspend_via_firmware() || !ctrl->npss || !pcie_aspm_enabled(pdev) || - ndev->nr_host_mem_descs || (ndev->ctrl.quirks & NVME_QUIRK_SIMPLE_SUSPEND)) return nvme_disable_prepare_reset(ndev, true); @@ -3131,6 +3130,17 @@ static int nvme_suspend(struct device *dev) if (ctrl->state != NVME_CTRL_LIVE) goto unfreeze; + /* + * Host memory access may not be successful in a system suspend state, + * but the specification allows the controller to access memory in a + * non-operational power state. + */ + if (ndev->hmb) { + ret = nvme_set_host_mem(ndev, 0); + if (ret < 0) + goto unfreeze; + } + ret = nvme_get_power_state(ctrl, &ndev->last_ps); if (ret < 0) goto unfreeze; -- 2.39.5