On Mon, 5 Jun 2017, Peter Chen wrote: > On Thu, May 18, 2017 at 08:49:00AM +0800, Peter Chen wrote: > > Some hard-wired USB devices need to do power sequence to let the > > device work normally, the typical power sequence like: enable USB > > PHY clock, toggle reset pin, etc. But current Linux USB driver > > lacks of such code to do it, it may cause some hard-wired USB devices > > works abnormal or can't be recognized by controller at all. > > > > In this patch, it calls power sequence library APIs to finish > > the power sequence events. It will do power on sequence at hub's > > probe for all devices under this hub (includes root hub). > > At hub_disconnect, it will do power off sequence which is at powered > > on list. > > > > Greg, Alan, would you please help on reviewing it? It seems Rafael > is waiting for USB MAINTAINERS's comments or ack. It resolves some > USB HUB issues for several persons. > > Peter > > > Signed-off-by: Peter Chen <peter.c...@nxp.com> > > Tested-by Joshua Clayton <stillcompil...@gmail.com> > > Tested-by: Maciej S. Szmigiero <m...@maciej.szmigiero.name> > > Reviewed-by: Vaibhav Hiremath <hvaibhav.li...@gmail.com>
Acked-by: Alan Stern <st...@rowland.harvard.edu> > > --- > > drivers/usb/Kconfig | 1 + > > drivers/usb/core/hub.c | 49 > > +++++++++++++++++++++++++++++++++++++++++++++---- > > drivers/usb/core/hub.h | 1 + > > 3 files changed, 47 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/usb/Kconfig b/drivers/usb/Kconfig > > index 939a63b..b6f626e 100644 > > --- a/drivers/usb/Kconfig > > +++ b/drivers/usb/Kconfig > > @@ -39,6 +39,7 @@ config USB > > tristate "Support for Host-side USB" > > depends on USB_ARCH_HAS_HCD > > select USB_COMMON > > + select POWER_SEQUENCE > > select NLS # for UTF-8 strings > > ---help--- > > Universal Serial Bus (USB) is a specification for a serial bus > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > > index 9dca59e..7a67296 100644 > > --- a/drivers/usb/core/hub.c > > +++ b/drivers/usb/core/hub.c > > @@ -28,6 +28,7 @@ > > #include <linux/mutex.h> > > #include <linux/random.h> > > #include <linux/pm_qos.h> > > +#include <linux/power/pwrseq.h> > > > > #include <linux/uaccess.h> > > #include <asm/byteorder.h> > > @@ -1619,6 +1620,7 @@ static void hub_disconnect(struct usb_interface *intf) > > hub->error = 0; > > hub_quiesce(hub, HUB_DISCONNECT); > > > > + of_pwrseq_off_list(&hub->pwrseq_on_list); Things like this look a little peculiar -- you are passing an "on_list" to a function named "...off_list". How about naming the new field hub->pwrseq_list instead? Alan Stern
