diff options
| -rw-r--r-- | drivers/usb/core/hub.c | 414 | ||||
| -rw-r--r-- | include/linux/usb.h | 21 | ||||
| -rw-r--r-- | include/linux/usb/ch11.h | 2 | ||||
| -rw-r--r-- | include/linux/usb/ch9.h | 45 | ||||
| -rw-r--r-- | include/linux/usb/hcd.h | 9 |
5 files changed, 489 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 5219507bf227..fd1ec481aec1 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -3050,11 +3050,425 @@ void usb_root_hub_lost_power(struct usb_device *rhdev) } EXPORT_SYMBOL_GPL(usb_root_hub_lost_power); +static const char * const usb3_lpm_names[] = { + "U0", + "U1", + "U2", + "U3", +}; + +/* + * Send a Set SEL control transfer to the device, prior to enabling + * device-initiated U1 or U2. This lets the device know the exit latencies from + * the time the device initiates a U1 or U2 exit, to the time it will receive a + * packet from the host. + * + * This function will fail if the SEL or PEL values for udev are greater than + * the maximum allowed values for the link state to be enabled. + */ +static int usb_req_set_sel(struct usb_device *udev, enum usb3_link_state state) +{ + struct usb_set_sel_req *sel_values; + unsigned long long u1_sel; + unsigned long long u1_pel; + unsigned long long u2_sel; + unsigned long long u2_pel; + int ret; + + /* Convert SEL and PEL stored in ns to us */ + u1_sel = DIV_ROUND_UP(udev->u1_params.sel, 1000); + u1_pel = DIV_ROUND_UP(udev->u1_params.pel, 1000); + u2_sel = DIV_ROUND_UP(udev->u2_params.sel, 1000); + u2_pel = DIV_ROUND_UP(udev->u2_params.pel, 1000); + + /* + * Make sure that the calculated SEL and PEL values for the link + * state we're enabling aren't bigger than the max SEL/PEL + * value that will fit in the SET SEL control transfer. + * Otherwise the device would get an incorrect idea of the exit + * latency for the link state, and could start a device-initiated + * U1/U2 when the exit latencies are too high. + */ + if ((state == USB3_LPM_U1 && + (u1_sel > USB3_LPM_MAX_U1_SEL_PEL || + u1_pel > USB3_LPM_MAX_U1_SEL_PEL)) || + (state == USB3_LPM_U2 && + (u2_sel > USB3_LPM_MAX_U2_SEL_PEL || + u2_pel > USB3_LPM_MAX_U2_SEL_PEL))) { + dev_dbg(&udev->dev, "Device-initiated %s disabled due " + "to long SEL %llu ms or PEL %llu ms\n", + usb3_lpm_names[state], u1_sel, u1_pel); + return -EINVAL; + } + + /* + * If we're enabling device-initiated LPM for one link state, + * but the other link state has a too high SEL or PEL value, + * just set those values to the max in the Set SEL request. + */ + if (u1_sel > USB3_LPM_MAX_U1_SEL_PEL) + u1_sel = USB3_LPM_MAX_U1_SEL_PEL; + + if (u1_pel > USB3_LPM_MAX_U1_SEL_PEL) + u1_pel = USB3_LPM_MAX_U1_SEL_PEL; + + if (u2_sel > USB3_LPM_MAX_U2_SEL_PEL) + u2_sel = USB3_LPM_MAX_U2_SEL_PEL; + + if (u2_pel > USB3_LPM_MAX_U2_SEL_PEL) + u2_pel = USB3_LPM_MAX_U2_SEL_PEL; + + /* + * usb_enable_lpm() can be called as part of a failed device reset, + * which may be initiated by an error path of a mass storage driver. + * Therefore, use GFP_NOIO. + */ + sel_values = kmalloc(sizeof *(sel_values), GFP_NOIO); + if (!sel_values) + return -ENOMEM; + + sel_values->u1_sel = u1_sel; + sel_values->u1_pel = u1_pel; + sel_values->u2_sel = cpu_to_le16(u2_sel); + sel_values->u2_pel = cpu_to_le16(u2_pel); + + ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), + USB_REQ_SET_SEL, + USB_RECIP_DEVICE, + 0, 0, + sel_values, sizeof *(sel_values), + USB_CTRL_SET_TIMEOUT); + kfree(sel_values); + return ret; +} + +/* + * Enable or disable device-initiated U1 or U2 transitions. + */ +static int usb_set_device_initiated_lpm(struct usb_device *udev, + enum usb3_link_state state, bool enable) +{ + int ret; + int feature; + + switch (state) { + case USB3_LPM_U1: + feature = USB_DEVICE_U1_ENABLE; + break; + case USB3_LPM_U2: + feature = USB_DEVICE_U2_ENABLE; + break; + default: + dev_warn(&udev->dev, "%s: Can't %s non-U1 or U2 state.\n", + __func__, enable ? "enable" : "disable"); + return -EINVAL; + } + + if (udev->state != USB_STATE_CONFIGURED) { + dev_dbg(&udev->dev, "%s: Can't %s %s state " + "for unconfigured device.\n", + __func__, enable ? "enable" : "disable", + usb3_lpm_names[state]); + return 0; + } + + if (enable) { + /* + * First, let the device know about the exit latencies + * associated with the link state we're about to enable. + */ + ret = usb_req_set_sel(udev, state); + if (ret < 0) { + dev_warn(&udev->dev, "Set SEL for device-initiated " + "%s failed.\n", usb3_lpm_names[state]); + return -EBUSY; + } + /* + * Now send the control transfer to enable device-initiated LPM + * for either U1 or U2. + */ + ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), + USB_REQ_SET_FEATURE, + USB_RECIP_DEVICE, + feature, + 0, NULL, 0, + USB_CTRL_SET_TIMEOUT); + } else { + ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0), + USB_REQ_CLEAR_FEATURE, + USB_RECIP_DEVICE, + feature, + 0, NULL, 0, + USB_CTRL_SET_TIMEOUT); + } + if (ret < 0) { + dev_warn(&udev->dev, "%s of device-initiated %s failed.\n", + enable ? "Enable" : "Disable", + usb3_lpm_names[state]); + return -EBUSY; + } + return 0; +} + +static int usb_set_lpm_timeout(struct usb_device *udev, + enum usb3_link_state state, int timeout) +{ + int ret; + int feature; + + switch (state) { + case USB3_LPM_U1: + feature = USB_PORT_FEAT_U1_TIMEOUT; + break; + case USB3_LPM_U2: + feature = USB_PORT_FEAT_U2_TIMEOUT; + break; + default: + dev_warn(&udev->dev, "%s: Can't set timeout for non-U1 or U2 state.\n", + __func__); + return -EINVAL; + } + + if (state == USB3_LPM_U1 && timeout > USB3_LPM_U1_MAX_TIMEOUT && + timeout != USB3_LPM_DEVICE_INITIATED) { + dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x, " + "which is a reserved value.\n", + usb3_lpm_names[state], timeout); + return -EINVAL; + } + + ret = set_port_feature(udev->parent, + USB_PORT_LPM_TIMEOUT(timeout) | udev->portnum, + feature); + if (ret < 0) { + dev_warn(&udev->dev, "Failed to set %s timeout to 0x%x," + "error code %i\n", usb3_lpm_names[state], + timeout, ret); + return -EBUSY; + } + if (state == USB3_LPM_U1) + udev->u1_params.timeout = timeout; + else + udev->u2_params.timeout = timeout; + return 0; +} + +/* + * Enable the hub-initiated U1/U2 idle timeouts, and enable device-initiated + * U1/U2 entry. + * + * We will attempt to enable U1 or U2, but there are no guarantees that the + * control transfers to set the hub timeout or enable device-initiated U1/U2 + * will be successful. + * + * If we cannot set the parent hub U1/U2 timeout, we attempt to let the xHCI + * driver know about it. If that call fails, it should be harmless, and just + * take up more slightly more bus bandwidth for unnecessary U1/U2 exit latency. + */ +static void usb_enable_link_state(struct usb_hcd *hcd, struct usb_device *udev, + enum usb3_link_state state) +{ + int timeout; + + /* We allow the host controller to set the U1/U2 timeout internally + * first, so that it can change its schedule to account for the + * additional latency to send data to a device in a lower power + * link state. + */ + timeout = hcd->driver->enable_usb3_lpm_timeout(hcd, udev, state); + + /* xHCI host controller doesn't want to enable this LPM state. */ + if (timeout == 0) + return; + + if (timeout < 0) { + dev_warn(&udev->dev, "Could not enable %s link state, " + "xHCI error %i.\n", usb3_lpm_names[state], + timeout); + return; + } + + if (usb_set_lpm_timeout(udev, state, timeout)) + /* If we can't set the parent hub U1/U2 timeout, + * device-initiated LPM won't be allowed either, so let the xHCI + * host know that this link state won't be enabled. + */ + hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state); + + /* Only a configured device will accept the Set Feature U1/U2_ENABLE */ + else if (udev->actconfig) + usb_set_device_initiated_lpm(udev, state, true); + +} + +/* + * Disable the hub-initiated U1/U2 idle timeouts, and disable device-initiated + * U1/U2 entry. + * + * If this function returns -EBUSY, the parent hub will still allow U1/U2 entry. + * If zero is returned, the parent will not allow the link to go into U1/U2. + * + * If zero is returned, device-initiated U1/U2 entry may still be enabled, but + * it won't have an effect on the bus link state because the parent hub will + * still disallow device-initiated U1/U2 entry. + * + * If zero is returned, the xHCI host controller may still think U1/U2 entry is + * possible. The result will be slightly more bus bandwidth will be taken up + * (to account for U1/U2 exit latency), but it should be harmless. + */ +static int usb_disable_link_state(struct usb_hcd *hcd, struct usb_device *udev, + enum usb3_link_state state) +{ + int feature; + + switch (state) { + case USB3_LPM_U1: + feature = USB_PORT_FEAT_U1_TIMEOUT; + break; + case USB3_LPM_U2: + feature = USB_PORT_FEAT_U2_TIMEOUT; + break; + default: + dev_warn(&udev->dev, "%s: Can't disable non-U1 or U2 state.\n", + __func__); + return -EINVAL; + } + + if (usb_set_lpm_timeout(udev, state, 0)) + return -EBUSY; + + usb_set_device_initiated_lpm(udev, state, false); + + if (hcd->driver->disable_usb3_lpm_timeout(hcd, udev, state)) + dev_warn(&udev->dev, "Could not disable xHCI %s timeout, " + "bus schedule bandwidth may be impacted.\n", + usb3_lpm_names[state]); + return 0; +} + +/* + * Disable hub-initiated and device-initiated U1 and U2 entry. + * Caller must own the bandwidth_mutex. + * + * This will call usb_enable_lpm() on failure, which will decrement + * lpm_disable_count, and will re-enable LPM if lpm_disable_count reaches zero. + */ +int usb_disable_lpm(struct usb_device *udev) +{ + struct usb_hcd *hcd; + + if (!udev || !udev->parent || + udev->speed != USB_SPEED_SUPER || + !udev->lpm_capable) + return 0; + + hcd = bus_to_hcd(udev->bus); + if (!hcd || !hcd->driver->disable_usb3_lpm_timeout) + return 0; + + udev->lpm_disable_count++; + if ((udev->u1_params.timeout == 0 && udev->u1_params.timeout == 0)) + return 0; + + /* If LPM is enabled, attempt to disable it. */ + if (usb_disable_link_state(hcd, udev, USB3_LPM_U1)) + goto enable_lpm; + if (usb_disable_link_state(hcd, udev, USB3_LPM_U2)) + goto enable_lpm; + + return 0; + +enable_lpm: + usb_enable_lpm(udev); + return -EBUSY; +} +EXPORT_SYMBOL_GPL(usb_disable_lpm); + +/* Grab the bandwidth_mutex before calling usb_disable_lpm() */ +int usb_unlocked_disable_lpm(struct usb_device *udev) +{ + struct usb_hcd *hcd = bus_to_hcd(udev->bus); + int ret; + + if (!hcd) + return -EINVAL; + + mutex_lock(hcd->bandwidth_mutex); + ret = usb_disable_lpm(udev); + mutex_unlock(hcd->bandwidth_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(usb_unlocked_disable_lpm); + +/* + * Attempt to enable device-initiated and hub-initiated U1 and U2 entry. The + * xHCI host policy may prevent U1 or U2 from being enabled. + * + * Other callers may have disabled link PM, so U1 and U2 entry will be disabled + * until the lpm_disable_count drops to zero. Caller must own the + * bandwidth_mutex. + */ +void usb_enable_lpm(struct usb_device *udev) +{ + struct usb_hcd *hcd; + + if (!udev || !udev->parent || + udev->speed != USB_SPEED_SUPER || + !udev->lpm_capable) + return; + + udev->lpm_disable_count--; + hcd = bus_to_hcd(udev->bus); + /* Double check that we can both enable and disable LPM. + * Device must be configured to accept set feature U1/U2 timeout. + */ + if (!hcd || !hcd->driver->enable_usb3_lpm_timeout || + !hcd->driver->disable_usb3_lpm_timeout) + return; + + if (udev->lpm_disable_count > 0) + return; + + usb_enable_link_state(hcd, udev, USB3_LPM_U1); + usb_enable_link_state(hcd, udev, USB3_LPM_U2); +} +EXPORT_SYMBOL_GPL(usb_enable_lpm); + +/* Grab the bandwidth_mutex before calling usb_enable_lpm() */ +void usb_unlocked_enable_lpm(struct usb_device *udev) +{ + struct usb_hcd *hcd = bus_to_hcd(udev->bus); + + if (!hcd) + return; + + mutex_lock(hcd->bandwidth_mutex); + usb_enable_lpm(udev); + mutex_unlock(hcd->bandwidth_mutex); +} +EXPORT_SYMBOL_GPL(usb_unlocked_enable_lpm); + + #else /* CONFIG_PM */ #define hub_suspend NULL #define hub_resume NULL #define hub_reset_resume NULL + +int usb_disable_lpm(struct usb_device *udev) +{ + return 0; +} + +void usb_enable_lpm(struct usb_device *udev) { } + +int usb_unlocked_disable_lpm(struct usb_device *udev) +{ + return 0; +} + +void usb_unlocked_enable_lpm(struct usb_device *udev) { } #endif diff --git a/include/linux/usb.h b/include/linux/usb.h index 22e7b53123ef..40439dfd81a7 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -409,6 +409,12 @@ struct usb3_lpm_parameters { * it will get data. */ unsigned int sel; + /* + * The idle timeout value that is currently programmed into the parent + * hub for this device. When the timer counts to zero, the parent hub + * will initiate an LPM transition to either U1 or U2. + */ + int timeout; }; /** @@ -468,8 +474,12 @@ struct usb3_lpm_parameters { * specific data for the device. * @slot_id: Slot ID assigned by xHCI * @removable: Device can be physically removed from this port - * @u1_params: exit latencies for U1 (USB 3.0 LPM). - * @u2_params: exit latencies for U2 (USB 3.0 LPM). + * @u1_params: exit latencies for USB3 U1 LPM state, and hub-initiated timeout. + * @u2_params: exit latencies for USB3 U2 LPM state, and hub-initiated timeout. + * @lpm_disable_count: Ref count used by usb_disable_lpm() and usb_enable_lpm() + * to keep track of the number of functions that require USB 3.0 Link Power + * Management to be disabled for this usb_device. This count should only + * be manipulated by those functions, with the bandwidth_mutex is held. * * Notes: * Usbcore drivers should not set usbdev->state directly. Instead use @@ -544,6 +554,7 @@ struct usb_device { enum usb_device_removable removable; struct usb3_lpm_parameters u1_params; struct usb3_lpm_parameters u2_params; + unsigned lpm_disable_count; }; #define to_usb_device(d) container_of(d, struct usb_device, dev) @@ -579,6 +590,12 @@ extern void usb_autopm_put_interface_async(struct usb_interface *intf); extern void usb_autopm_get_interface_no_resume(struct usb_interface *intf); extern void usb_autopm_put_interface_no_suspend(struct usb_interface *intf); +extern int usb_disable_lpm(struct usb_device *udev); +extern void usb_enable_lpm(struct usb_device *udev); +/* Same as above, but these functions lock/unlock the bandwidth_mutex. */ +extern int usb_unlocked_disable_lpm(struct usb_device *udev); +extern void usb_unlocked_enable_lpm(struct usb_device *udev); + static inline void usb_mark_last_busy(struct usb_device *udev) { pm_runtime_mark_last_busy(&udev->dev); diff --git a/include/linux/usb/ch11.h b/include/linux/usb/ch11.h index f1d26b6067f1..b6c2863b2c94 100644 --- a/include/linux/usb/ch11.h +++ b/include/linux/usb/ch11.h @@ -76,6 +76,8 @@ #define USB_PORT_FEAT_C_BH_PORT_RESET 29 #define USB_PORT_FEAT_FORCE_LINKPM_ACCEPT 30 +#define USB_PORT_LPM_TIMEOUT(p) (((p) & 0xff) << 8) + /* USB 3.0 hub remote wake mask bits, see table 10-14 */ #define USB_PORT_FEAT_REMOTE_WAKE_CONNECT (1 << 8) #define USB_PORT_FEAT_REMOTE_WAKE_DISCONNECT (1 << 9) diff --git a/include/linux/usb/ch9.h b/include/linux/usb/ch9.h index e785d85b617f..43bce9da7a4d 100644 --- a/include/linux/usb/ch9.h +++ b/include/linux/usb/ch9.h @@ -935,6 +935,51 @@ enum usb_device_state { */ }; +enum usb3_link_state { + USB3_LPM_U0 = 0, + USB3_LPM_U1, + USB3_LPM_U2, + USB3_LPM_U3 +}; + +/* + * A U1 timeout of 0x0 means the parent hub will reject any transitions to U1. + * 0xff means the parent hub will accept transitions to U1, but will not + * initiate a transition. + * + * A U1 timeout of 0x1 to 0x7F also causes the hub to initiate a transition to + * U1 after that many microseconds. Timeouts of 0x80 to 0xFE are reserved + * values. + * + * A U2 timeout of 0x0 means the parent hub will reject any transitions to U2. + * 0xff means the parent hub will accept transitions to U2, but will not + * initiate a transition. + * + * A U2 timeout of 0x1 to 0xFE also causes the hub to initiate a transition to + * U2 after N*256 microseconds. Therefore a U2 timeout value of 0x1 means a U2 + * idle timer of 256 microseconds, 0x2 means 512 microseconds, 0xFE means + * 65.024ms. + */ +#define USB3_LPM_DISABLED 0x0 +#define USB3_LPM_U1_MAX_TIMEOUT 0x7F +#define USB3_LPM_U2_MAX_TIMEOUT 0xFE +#define USB3_LPM_DEVICE_INITIATED 0xFF + +struct usb_set_sel_req { + __u8 u1_sel; + __u8 u1_pel; + __le16 u2_sel; + __le16 u2_pel; +} __attribute__ ((packed)); + +/* + * The Set System Exit Latency control transfer provides one byte each for + * U1 SEL and U1 PEL, so the max exit latency is 0xFF. U2 SEL and U2 PEL each + * are two bytes long. + */ +#define USB3_LPM_MAX_U1_SEL_PEL 0xFF +#define USB3_LPM_MAX_U2_SEL_PEL 0xFFFF + /*-------------------------------------------------------------------------*/ /* diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h index bbb946437070..7f855d50cdf5 100644 --- a/include/linux/usb/hcd.h +++ b/include/linux/usb/hcd.h @@ -344,6 +344,15 @@ struct hc_driver { */ int (*update_device)(struct usb_hcd *, struct usb_device *); int (*set_usb2_hw_lpm)(struct usb_hcd *, struct usb_device *, int); + /* USB 3.0 Link Power Management */ + /* Returns the USB3 hub-encoded value for the U1/U2 timeout. */ + int (*enable_usb3_lpm_timeout)(struct usb_hcd *, + struct usb_device *, enum usb3_link_state state); + /* The xHCI host controller can still fail the command to + * disable the LPM timeouts, so this can return an error code. + */ + int (*disable_usb3_lpm_timeout)(struct usb_hcd *, + struct usb_device *, enum usb3_link_state state); }; extern int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb); |
