2017-06-05 06:55:47

by Peter Chen

[permalink] [raw]
Subject: Re: [PATCH v14 4/7] usb: core: add power sequence handling for USB devices

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 <[email protected]>
> Tested-by Joshua Clayton <[email protected]>
> Tested-by: Maciej S. Szmigiero <[email protected]>
> Reviewed-by: Vaibhav Hiremath <[email protected]>
> ---
> 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);
> mutex_lock(&usb_port_peer_mutex);
>
> /* Avoid races with recursively_mark_NOTATTACHED() */
> @@ -1646,12 +1648,42 @@ static void hub_disconnect(struct usb_interface *intf)
> kref_put(&hub->kref, hub_release);
> }
>
> +#ifdef CONFIG_OF
> +static int hub_of_pwrseq_on(struct usb_hub *hub)
> +{
> + struct device *parent;
> + struct usb_device *hdev = hub->hdev;
> + struct device_node *np;
> + int ret;
> +
> + if (hdev->parent)
> + parent = &hdev->dev;
> + else
> + parent = bus_to_hcd(hdev->bus)->self.sysdev;
> +
> + for_each_child_of_node(parent->of_node, np) {
> + ret = of_pwrseq_on_list(np, &hub->pwrseq_on_list);
> + /* Maybe no power sequence library is chosen */
> + if (ret && ret != -ENOENT)
> + return ret;
> + }
> +
> + return 0;
> +}
> +#else
> +static int hub_of_pwrseq_on(struct usb_hub *hub)
> +{
> + return 0;
> +}
> +#endif
> +
> static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> {
> struct usb_host_interface *desc;
> struct usb_endpoint_descriptor *endpoint;
> struct usb_device *hdev;
> struct usb_hub *hub;
> + int ret = -ENODEV;
>
> desc = intf->cur_altsetting;
> hdev = interface_to_usbdev(intf);
> @@ -1756,6 +1788,7 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> INIT_DELAYED_WORK(&hub->leds, led_work);
> INIT_DELAYED_WORK(&hub->init_work, NULL);
> INIT_WORK(&hub->events, hub_event);
> + INIT_LIST_HEAD(&hub->pwrseq_on_list);
> usb_get_intf(intf);
> usb_get_dev(hdev);
>
> @@ -1769,11 +1802,14 @@ static int hub_probe(struct usb_interface *intf, const struct usb_device_id *id)
> if (id->driver_info & HUB_QUIRK_CHECK_PORT_AUTOSUSPEND)
> hub->quirk_check_port_auto_suspend = 1;
>
> - if (hub_configure(hub, endpoint) >= 0)
> - return 0;
> + if (hub_configure(hub, endpoint) >= 0) {
> + ret = hub_of_pwrseq_on(hub);
> + if (!ret)
> + return 0;
> + }
>
> hub_disconnect(intf);
> - return -ENODEV;
> + return ret;
> }
>
> static int
> @@ -3593,14 +3629,19 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
>
> /* stop hub_wq and related activity */
> hub_quiesce(hub, HUB_SUSPEND);
> - return 0;
> + return pwrseq_suspend_list(&hub->pwrseq_on_list);
> }
>
> static int hub_resume(struct usb_interface *intf)
> {
> struct usb_hub *hub = usb_get_intfdata(intf);
> + int ret;
>
> dev_dbg(&intf->dev, "%s\n", __func__);
> + ret = pwrseq_resume_list(&hub->pwrseq_on_list);
> + if (ret)
> + return ret;
> +
> hub_activate(hub, HUB_RESUME);
> return 0;
> }
> diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
> index 34c1a7e..cd86f91 100644
> --- a/drivers/usb/core/hub.h
> +++ b/drivers/usb/core/hub.h
> @@ -78,6 +78,7 @@ struct usb_hub {
> struct delayed_work init_work;
> struct work_struct events;
> struct usb_port **ports;
> + struct list_head pwrseq_on_list; /* powered pwrseq node list */
> };
>
> /**
> --
> 2.7.4
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

--

Best Regards,
Peter Chen


2017-06-05 14:16:38

by Alan Stern

[permalink] [raw]
Subject: Re: [PATCH v14 4/7] usb: core: add power sequence handling for USB devices

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 <[email protected]>
> > Tested-by Joshua Clayton <[email protected]>
> > Tested-by: Maciej S. Szmigiero <[email protected]>
> > Reviewed-by: Vaibhav Hiremath <[email protected]>

Acked-by: Alan Stern <[email protected]>

> > ---
> > 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

2017-06-06 01:32:31

by Peter Chen

[permalink] [raw]
Subject: Re: [PATCH v14 4/7] usb: core: add power sequence handling for USB devices

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 <[email protected]>
> > > Tested-by Joshua Clayton <[email protected]>
> > > Tested-by: Maciej S. Szmigiero <[email protected]>
> > > Reviewed-by: Vaibhav Hiremath <[email protected]>
>
> Acked-by: Alan Stern <[email protected]>
>
> > > ---
> > > 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?
>

Thanks, Alan. I will change it at next revision.

--

Best Regards,
Peter Chen