This driver often takes on the order of 8ms to start, but every little
bit counts. It shouldn't have many cross-device dependencies to
race with, nor racy access to shared state with other drivers, so this
should be a relatively low risk change.
This driver was pinpointed as part of a survey of top slowest initcalls
(i.e., are built in, and probing synchronously) on a lab of ChromeOS
systems.
Signed-off-by: Brian Norris <[email protected]>
---
drivers/usb/host/ehci-pci.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 17f8b6ea0c35..4b148fe5e43b 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -411,11 +411,12 @@ static struct pci_driver ehci_pci_driver = {
.remove = ehci_pci_remove,
.shutdown = usb_hcd_pci_shutdown,
-#ifdef CONFIG_PM
.driver = {
- .pm = &usb_hcd_pci_pm_ops
- },
+#ifdef CONFIG_PM
+ .pm = &usb_hcd_pci_pm_ops,
#endif
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
};
static int __init ehci_pci_init(void)
--
2.38.1.273.g43a17bfeac-goog
On Fri, Oct 28, 2022 at 02:19:07PM -0700, Brian Norris wrote:
> This driver often takes on the order of 8ms to start, but every little
> bit counts. It shouldn't have many cross-device dependencies to
> race with, nor racy access to shared state with other drivers, so this
> should be a relatively low risk change.
>
> This driver was pinpointed as part of a survey of top slowest initcalls
> (i.e., are built in, and probing synchronously) on a lab of ChromeOS
> systems.
>
> Signed-off-by: Brian Norris <[email protected]>
> ---
Acked-by: Alan Stern <[email protected]>
However, I'm curious to know why this patch makes ehci-pci use
PROBE_PREFER_ASYNCHRONOUS even when CONFIG_PM isn't set, whereas the 2/2
patch makes xhci-pci use PROBE_PREFER_ASYNCHRONOUS only when CONFIG_PM
is set.
Alan Stern
> drivers/usb/host/ehci-pci.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
> index 17f8b6ea0c35..4b148fe5e43b 100644
> --- a/drivers/usb/host/ehci-pci.c
> +++ b/drivers/usb/host/ehci-pci.c
> @@ -411,11 +411,12 @@ static struct pci_driver ehci_pci_driver = {
> .remove = ehci_pci_remove,
> .shutdown = usb_hcd_pci_shutdown,
>
> -#ifdef CONFIG_PM
> .driver = {
> - .pm = &usb_hcd_pci_pm_ops
> - },
> +#ifdef CONFIG_PM
> + .pm = &usb_hcd_pci_pm_ops,
> #endif
> + .probe_type = PROBE_PREFER_ASYNCHRONOUS,
> + },
> };
>
> static int __init ehci_pci_init(void)
> --
> 2.38.1.273.g43a17bfeac-goog
>
On Fri, Oct 28, 2022 at 09:13:14PM -0400, Alan Stern wrote:
> However, I'm curious to know why this patch makes ehci-pci use
> PROBE_PREFER_ASYNCHRONOUS even when CONFIG_PM isn't set, whereas the 2/2
> patch makes xhci-pci use PROBE_PREFER_ASYNCHRONOUS only when CONFIG_PM
> is set.
That's definitely a bug in patch 2. This has nothing (or, little; probe
order can technically affect the PM suspend/resume order) to do with
CONFIG_PM, except that the .pm hooks tend to sit nearby, and repeated
driver patching makes the author's eyes glaze over sometimes...
Thanks. v2 coming.
Brian