From 0a5ef95923e01aa93210d22e0d62d66b601238d7 Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Wed, 15 Nov 2023 13:17:17 +0100 Subject: [PATCH] PCI: Add debug print for device ready delay Currently, the time it took a PCI device to become ready after reset is only printed if it was longer than 1000ms ('PCI_RESET_WAIT'). However, for debugging purposes it is useful to know this time even if it was shorter. For example, with the device I am working on, hardware engineers asked to verify that it becomes ready on the first try (no delay). To that end, add a debug level print that can be enabled using dynamic debug. Example: # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset # dmesg -c | grep ready # echo "file drivers/pci/pci.c +p" > /sys/kernel/debug/dynamic_debug/control # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset # dmesg -c | grep ready [ 396.060335] mlxsw_spectrum4 0000:01:00.0: ready 0ms after bus reset # echo "file drivers/pci/pci.c -p" > /sys/kernel/debug/dynamic_debug/control # echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset # dmesg -c | grep ready Signed-off-by: Ido Schimmel Acked-by: Bjorn Helgaas Signed-off-by: Petr Machata Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- drivers/pci/pci.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 55bc3576a9856..69d20d585f889 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -1219,6 +1219,9 @@ static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) if (delay > PCI_RESET_WAIT) pci_info(dev, "ready %dms after %s\n", delay - 1, reset_type); + else + pci_dbg(dev, "ready %dms after %s\n", delay - 1, + reset_type); return 0; } -- 2.30.2