From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: [PATCH v3 3/3] PCI: Intel DC P3700 NVMe delay after FLR quirk From: Alex Williamson To: linux-pci@vger.kernel.org Date: Tue, 24 Jul 2018 10:14:46 -0600 Message-ID: <20180724161446.2729.78211.stgit@gimli.home> In-Reply-To: <20180724160440.2729.75178.stgit@gimli.home> References: <20180724160440.2729.75178.stgit@gimli.home> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: Add a device specific reset for Intel DC P3700 NVMe device which exhibits a timeout failure in drivers waiting for the ready status to update after NVMe enable if the driver interacts with the device too quickly after FLR. As this has been observed in device assignment scenarios, resolve this with a device specific reset quirk to add an additional, heuristically determined, delay after the FLR completes. Signed-off-by: Alex Williamson --- drivers/pci/quirks.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c index 3899cdd2514b..08fafd804588 100644 --- a/drivers/pci/quirks.c +++ b/drivers/pci/quirks.c @@ -3751,6 +3751,27 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe) return 0; } +/* + * Intel DC P3700 NVMe controller will timeout waiting for ready status + * to change after NVMe enable if the driver starts interacting with the + * device too quickly after FLR. A 250ms delay after FLR has heuristically + * proven to produce reliably working results for device assignment cases. + */ +static int delay_250ms_after_flr(struct pci_dev *dev, int probe) +{ + if (!pcie_has_flr(dev)) + return -ENOTTY; + + if (probe) + return 0; + + pcie_flr(dev); + + msleep(250); + + return 0; +} + static const struct pci_dev_reset_methods pci_dev_reset_methods[] = { { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82599_SFP_VF, reset_intel_82599_sfp_virtfn }, @@ -3759,6 +3780,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = { { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_IVB_M2_VGA, reset_ivb_igd }, { PCI_VENDOR_ID_SAMSUNG, 0xa804, nvme_disable_and_flr }, + { PCI_VENDOR_ID_INTEL, 0x0953, delay_250ms_after_flr }, { PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID, reset_chelsio_generic_dev }, { 0 } _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme