| Message ID | 20250416144917.16822-4-guanyulin@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | Support system sleep with offloaded usb transfers | expand |
On Wed, Apr 16, 2025 at 02:43:03PM +0000, Guan-Yu Lin wrote: > The existing sideband driver only registers sidebands without tracking > their active usage. To address this, sideband will now record its active > usage when it creates/removes interrupters. In addition, a new api is > introduced to provide a means for other dirvers to fetch sideband > activity information on a USB host controller. > > Signed-off-by: Guan-Yu Lin <guanyulin@google.com> > --- > drivers/usb/host/xhci-sideband.c | 43 +++++++++++++++++++++++++++++++ > include/linux/usb/xhci-sideband.h | 9 +++++++ > 2 files changed, 52 insertions(+) > > diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c > index d49f9886dd84..67f31b0ec726 100644 > --- a/drivers/usb/host/xhci-sideband.c > +++ b/drivers/usb/host/xhci-sideband.c > @@ -266,6 +266,31 @@ xhci_sideband_get_event_buffer(struct xhci_sideband *sb) > } > EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer); > > +#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) > +/** > + * xhci_sideband_check - check the existence of active sidebands > + * @hcd: the host controller driver associated with the target host controller > + * > + * Allow other drivers, such as usb controller driver, to check if there are > + * any sideband activity on the host controller. This information could be used > + * for power management or other forms of resource management. > + * > + * Returns true on any active sideband existence, false otherwise. > + */ > +bool xhci_sideband_check(struct usb_hcd *hcd) > +{ > + struct usb_device *udev = hcd->self.root_hub; > + bool active; > + > + device_lock(&udev->dev); > + active = usb_offload_check(udev); > + device_unlock(&udev->dev); > + > + return active; What happens if the value changes right after reading it? What are you going to do with the value? > +} > +EXPORT_SYMBOL_GPL(xhci_sideband_check); > +#endif /* IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) */ > + > /** > * xhci_sideband_create_interrupter - creates a new interrupter for this sideband > * @sb: sideband instance for this usb device > @@ -286,6 +311,7 @@ xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg, > bool ip_autoclear, u32 imod_interval, int intr_num) > { > int ret = 0; > + struct usb_device *udev; > > if (!sb || !sb->xhci) > return -ENODEV; > @@ -304,6 +330,11 @@ xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg, > goto out; > } > > + udev = sb->vdev->udev; > + device_lock(&udev->dev); > + ret = usb_offload_get(udev); > + device_unlock(&udev->dev); A "raw" call to device_lock/unlock feels rough, and harsh, why doesn't the function do that itself? thanks, greg k-h
diff --git a/drivers/usb/host/xhci-sideband.c b/drivers/usb/host/xhci-sideband.c index d49f9886dd84..67f31b0ec726 100644 --- a/drivers/usb/host/xhci-sideband.c +++ b/drivers/usb/host/xhci-sideband.c @@ -266,6 +266,31 @@ xhci_sideband_get_event_buffer(struct xhci_sideband *sb) } EXPORT_SYMBOL_GPL(xhci_sideband_get_event_buffer); +#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) +/** + * xhci_sideband_check - check the existence of active sidebands + * @hcd: the host controller driver associated with the target host controller + * + * Allow other drivers, such as usb controller driver, to check if there are + * any sideband activity on the host controller. This information could be used + * for power management or other forms of resource management. + * + * Returns true on any active sideband existence, false otherwise. + */ +bool xhci_sideband_check(struct usb_hcd *hcd) +{ + struct usb_device *udev = hcd->self.root_hub; + bool active; + + device_lock(&udev->dev); + active = usb_offload_check(udev); + device_unlock(&udev->dev); + + return active; +} +EXPORT_SYMBOL_GPL(xhci_sideband_check); +#endif /* IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) */ + /** * xhci_sideband_create_interrupter - creates a new interrupter for this sideband * @sb: sideband instance for this usb device @@ -286,6 +311,7 @@ xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg, bool ip_autoclear, u32 imod_interval, int intr_num) { int ret = 0; + struct usb_device *udev; if (!sb || !sb->xhci) return -ENODEV; @@ -304,6 +330,11 @@ xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg, goto out; } + udev = sb->vdev->udev; + device_lock(&udev->dev); + ret = usb_offload_get(udev); + device_unlock(&udev->dev); + sb->ir->ip_autoclear = ip_autoclear; out: @@ -323,6 +354,8 @@ EXPORT_SYMBOL_GPL(xhci_sideband_create_interrupter); void xhci_sideband_remove_interrupter(struct xhci_sideband *sb) { + struct usb_device *udev; + if (!sb || !sb->ir) return; @@ -330,6 +363,16 @@ xhci_sideband_remove_interrupter(struct xhci_sideband *sb) xhci_remove_secondary_interrupter(xhci_to_hcd(sb->xhci), sb->ir); sb->ir = NULL; + udev = sb->vdev->udev; + + if (udev->state == USB_STATE_NOTATTACHED) { + usb_offload_put(udev); + } else { + device_lock(&udev->dev); + usb_offload_put(udev); + device_unlock(&udev->dev); + } + mutex_unlock(&sb->mutex); } EXPORT_SYMBOL_GPL(xhci_sideband_remove_interrupter); diff --git a/include/linux/usb/xhci-sideband.h b/include/linux/usb/xhci-sideband.h index 45288c392f6e..5174cc5afc98 100644 --- a/include/linux/usb/xhci-sideband.h +++ b/include/linux/usb/xhci-sideband.h @@ -11,6 +11,7 @@ #include <linux/scatterlist.h> #include <linux/usb.h> +#include <linux/usb/hcd.h> #define EP_CTX_PER_DEV 31 /* FIXME defined twice, from xhci.h */ @@ -83,6 +84,14 @@ xhci_sideband_get_endpoint_buffer(struct xhci_sideband *sb, struct usb_host_endpoint *host_ep); struct sg_table * xhci_sideband_get_event_buffer(struct xhci_sideband *sb); + +#if IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) +bool xhci_sideband_check(struct usb_hcd *hcd); +#else +static inline bool xhci_sideband_check(struct usb_hcd *hcd) +{ return false; } +#endif /* IS_ENABLED(CONFIG_USB_XHCI_SIDEBAND_SUSPEND) */ + int xhci_sideband_create_interrupter(struct xhci_sideband *sb, int num_seg, bool ip_autoclear, u32 imod_interval, int intr_num);
The existing sideband driver only registers sidebands without tracking their active usage. To address this, sideband will now record its active usage when it creates/removes interrupters. In addition, a new api is introduced to provide a means for other dirvers to fetch sideband activity information on a USB host controller. Signed-off-by: Guan-Yu Lin <guanyulin@google.com> --- drivers/usb/host/xhci-sideband.c | 43 +++++++++++++++++++++++++++++++ include/linux/usb/xhci-sideband.h | 9 +++++++ 2 files changed, 52 insertions(+)