Meteor Lake VMD has a bug that the IRQ raises before the DMA region is ready, so the requested IO is considered never completed: [ 97.343423] nvme nvme0: I/O 259 QID 2 timeout, completion polled [ 97.343446] nvme nvme0: I/O 384 QID 3 timeout, completion polled [ 97.343459] nvme nvme0: I/O 320 QID 4 timeout, completion polled [ 97.343470] nvme nvme0: I/O 707 QID 5 timeout, completion polled The is documented as erratum MTL016 [0]. The suggested workaround is to "The VMD MSI interrupt-handler should initially perform a dummy register read to the MSI initiator device prior to any writes to ensure proper PCIe ordering." which essentially is adding a delay before the interrupt handling. Hence add a delay before handle interrupt to workaround the erratum. [0] https://edc.intel.com/content/www/us/en/design/products/platforms/details/meteor-lake-u-p/core-ultra-processor-specification-update/errata-details/#MTL016 Link: https://bugzilla.kernel.org/show_bug.cgi?id=217871 Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> --- drivers/pci/controller/vmd.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index a726de0af011..3433b3730f9c 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -16,6 +16,7 @@ #include <linux/srcu.h> #include <linux/rculist.h> #include <linux/rcupdate.h> +#include <linux/delay.h> #include <asm/irqdomain.h> @@ -74,6 +75,9 @@ enum vmd_features { * proper power management of the SoC. */ VMD_FEAT_BIOS_PM_QUIRK = (1 << 5), + + /* Erratum MTL016 */ + VMD_FEAT_INTERRUPT_QUIRK = (1 << 6), }; #define VMD_BIOS_PM_QUIRK_LTR 0x1003 /* 3145728 ns */ @@ -90,6 +94,8 @@ static DEFINE_IDA(vmd_instance_ida); */ static DEFINE_RAW_SPINLOCK(list_lock); +static bool interrupt_delay; + /** * struct vmd_irq - private data to map driver IRQ to the VMD shared vector * @node: list item for parent traversal. @@ -105,6 +111,7 @@ struct vmd_irq { struct vmd_irq_list *irq; bool enabled; unsigned int virq; + bool delay_irq; }; /** @@ -680,8 +687,11 @@ static irqreturn_t vmd_irq(int irq, void *data) int idx; idx = srcu_read_lock(&irqs->srcu); - list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node) + list_for_each_entry_rcu(vmdirq, &irqs->irq_list, node) { + if (interrupt_delay) + udelay(4); generic_handle_irq(vmdirq->virq); + } srcu_read_unlock(&irqs->srcu, idx); return IRQ_HANDLED; @@ -1015,6 +1025,9 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id) if (features & VMD_FEAT_OFFSET_FIRST_VECTOR) vmd->first_vec = 1; + if (features & VMD_FEAT_INTERRUPT_QUIRK) + interrupt_delay = true; + spin_lock_init(&vmd->cfg_lock); pci_set_drvdata(dev, vmd); err = vmd_enable_domain(vmd, features); @@ -1106,7 +1119,8 @@ static const struct pci_device_id vmd_ids[] = { {PCI_VDEVICE(INTEL, 0xa77f), .driver_data = VMD_FEATS_CLIENT,}, {PCI_VDEVICE(INTEL, 0x7d0b), - .driver_data = VMD_FEATS_CLIENT,}, + .driver_data = VMD_FEATS_CLIENT | + VMD_FEAT_INTERRUPT_QUIRK,}, {PCI_VDEVICE(INTEL, 0xad0b), .driver_data = VMD_FEATS_CLIENT,}, {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_VMD_9A0B), -- 2.43.0
