On Mon, Aug 05, 2024 at 10:19:17AM +0200, Paul Menzel wrote: > > > > > > > A better approach would be to add a sysfs boolean > > > > > > > attribute to the hub > > > > > > > driver to enable the 40-ms reset-recovery delay, and > > > > > > > make it default to > > > > > > > True. Then people who don't need the delay could disable it from > > > > > > > userspace, say by a udev rule. > > > > > > > > > > > > How would you name it? > > > > > > > > > > You could call it "long_reset_recovery". Anything like that would be > > > > > okay. > > > > > > > > Would it be useful to makes it an integer instead of a boolean, > > > > and allow to configure the delay: > > > > `extra_reset_recovery_delay_ms`? > > > > > > Sure, why not? Just so long as the default value matches the current > > > behavior. > > > > I hope, I am going to find time to take a stab at it. > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index 4b93c0bd1d4b..72dd16eaa73a 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -120,9 +120,16 @@ MODULE_PARM_DESC(use_both_schemes, > "try the other device initialization scheme if the " > "first one fails"); > > +static int extra_reset_recovery_delay_ms = 40; > +module_param(extra_reset_recovery_delay_ms, int, S_IRUGO | S_IWUSR); > +MODULE_PARM_DESC(extra_reset_recovery_delay_ms, > + "extra recovery delay for USB devices after reset in > milliseconds " > + "(default 40 ms"); This is a module parameter, not a sysfs attribute. Module parameters should be avoided if possible, because they are much less flexible than sysfs attributes. Alan Stern
