From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Chen Subject: Re: [PATCH v14 4/7] usb: core: add power sequence handling for USB devices Date: Tue, 6 Jun 2017 09:32:17 +0800 Message-ID: <20170606013217.GA26189@b29397-desktop> References: <20170605065537.GE20014@b29397-desktop> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-pm-owner@vger.kernel.org To: Alan Stern Cc: Peter Chen , gregkh@linuxfoundation.org, ulf.hansson@linaro.org, broonie@kernel.org, sre@kernel.org, robh+dt@kernel.org, shawnguo@kernel.org, "Rafael J. Wysocki" , dbaryshkov@gmail.com, mark.rutland@arm.com, heiko@sntech.de, stephen.boyd@linaro.org, frank.li@nxp.com, gary.bisson@boundarydevices.com, festevam@gmail.com, stillcompiling@gmail.com, arnd@arndb.de, vaibhav.hiremath@linaro.org, krzk@kernel.org, mka@chromium.org, devicetree@vger.kernel.org, mail@maciej.szmigiero.name, pawel.moll@arm.com, Linux-pm mailing list , s.hauer@pengutronix.de, troy.kisky@boundarydevices.com, linux-arm-kernel@lists.infradead.org, hverkuil@xs4all.nl, oscar@naiandei.net, USB List-Id: devicetree@vger.kernel.org On Mon, Jun 05, 2017 at 10:16:34AM -0400, Alan Stern wrote: > 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 > > > Tested-by Joshua Clayton > > > Tested-by: Maciej S. Szmigiero > > > Reviewed-by: Vaibhav Hiremath > > Acked-by: Alan Stern > > > > --- > > > 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 > > > #include > > > #include > > > +#include > > > > > > #include > > > #include > > > @@ -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? > Thanks, Alan. I will change it at next revision. -- Best Regards, Peter Chen