From 4f69bd16df1a38c32d5d207a96d1d86df4808f87 Mon Sep 17 00:00:00 2001 From: "Matthew R. Ochs" Date: Tue, 29 Nov 2016 12:00:40 -0600 Subject: [PATCH] PCI: Increase VPD access timeout to 125ms The PCI core uses a fixed 50ms timeout when waiting for VPD accesses to complete. When an access does not complete within this period, a warning is logged and an error returned to the caller. While this default timeout is valid for most hardware, some devices can experience longer access delays under certain circumstances. For example, one of the IBM CXL Flash devices can take up to ~120ms in a worst-case scenario. These types of devices can benefit from an extended timeout. To support devices with a longer access delay, increase the timeout in pci_vpd_wait() to 125ms. The PCI specification is silent with respect to VPD delays, therefore there is no concern for violating a threshold. Tested-by: Uma Krishnan Signed-off-by: Matthew R. Ochs Signed-off-by: Bjorn Helgaas Reviewed-by: Gavin Shan --- drivers/pci/access.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/access.c b/drivers/pci/access.c index db239547fefd..849afd4b3864 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -367,7 +367,7 @@ static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size) static int pci_vpd_wait(struct pci_dev *dev) { struct pci_vpd *vpd = dev->vpd; - unsigned long timeout = jiffies + msecs_to_jiffies(50); + unsigned long timeout = jiffies + msecs_to_jiffies(125); unsigned long max_sleep = 16; u16 status; int ret;