From 935f8f7a0123ffa0a2dd7234713dc2ebeeb08955 Mon Sep 17 00:00:00 2001 From: Vincent Whitchurch Date: Thu, 26 Jan 2023 11:47:10 +0100 Subject: [PATCH] um-virt-pci: Make max delay configurable There is a hard coded maximum time for which the driver busy-loops waiting for a response from the virtio device. This default time may be too short for some systems, so make it a module parameter so that it can be set via the kernel command line. Signed-off-by: Vincent Whitchurch Signed-off-by: Richard Weinberger --- arch/um/drivers/virt-pci.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c index 6884e1b..0aa71c0 100644 --- a/arch/um/drivers/virt-pci.c +++ b/arch/um/drivers/virt-pci.c @@ -54,7 +54,8 @@ static struct irq_domain *um_pci_inner_domain; static struct irq_domain *um_pci_msi_domain; static unsigned long um_pci_msi_used[BITS_TO_LONGS(MAX_MSI_VECTORS)]; -#define UM_VIRT_PCI_MAXDELAY 40000 +static unsigned int um_pci_max_delay_us = 40000; +module_param_named(max_delay_us, um_pci_max_delay_us, uint, 0644); struct um_pci_message_buffer { struct virtio_pcidev_msg hdr; @@ -155,7 +156,7 @@ static int um_pci_send_cmd(struct um_pci_device *dev, kfree(completed); if (WARN_ONCE(virtqueue_is_broken(dev->cmd_vq) || - ++delay_count > UM_VIRT_PCI_MAXDELAY, + ++delay_count > um_pci_max_delay_us, "um virt-pci delay: %d", delay_count)) { ret = -EIO; break; -- 2.7.4