From 9502c46cc9d39330b29d9dc27d8baff4f55d0abc Mon Sep 17 00:00:00 2001 From: Pratyush Anand Date: Fri, 4 Jul 2014 17:01:23 +0300 Subject: [PATCH] xhci: A default implementation for Ux timeout calculation and tier policy check As best case, a host controller should support U0 to U1 switching for the devices connected below any tier of hub level supported by usb specification. Therefore xhci_check_tier_policy should always return success as default implementation. A host should be able to issue LGO_Ux after the timeout calculated as per definition of system exit latency defined in C.1.5.2. Therefore xhci_calculate_ux_timeout returns ux_params.sel as the default implementation. Use default calculation in absence of any vendor specific limitations. Signed-off-by: Pratyush Anand Tested-by: Aymen Bouattay Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/xhci.c | 66 ++++++++++++++++++++++++++++++----------- 1 file changed, 48 insertions(+), 18 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index f07be65b4e70..b04fef1e4ff8 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -4288,8 +4288,7 @@ static u16 xhci_get_timeout_no_hub_lpm(struct usb_device *udev, return USB3_LPM_DISABLED; } -/* Returns the hub-encoded U1 timeout value. - * The U1 timeout should be the maximum of the following values: +/* The U1 timeout should be the maximum of the following values: * - For control endpoints, U1 system exit latency (SEL) * 3 * - For bulk endpoints, U1 SEL * 5 * - For interrupt endpoints: @@ -4297,7 +4296,8 @@ static u16 xhci_get_timeout_no_hub_lpm(struct usb_device *udev, * - Periodic EPs, max(105% of bInterval, U1 SEL * 2) * - For isochronous endpoints, max(105% of bInterval, U1 SEL * 2) */ -static u16 xhci_calculate_intel_u1_timeout(struct usb_device *udev, +static unsigned long long xhci_calculate_intel_u1_timeout( + struct usb_device *udev, struct usb_endpoint_descriptor *desc) { unsigned long long timeout_ns; @@ -4329,11 +4329,28 @@ static u16 xhci_calculate_intel_u1_timeout(struct usb_device *udev, return 0; } - /* The U1 timeout is encoded in 1us intervals. */ - timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 1000); - /* Don't return a timeout of zero, because that's USB3_LPM_DISABLED. */ + return timeout_ns; +} + +/* Returns the hub-encoded U1 timeout value. */ +static u16 xhci_calculate_u1_timeout(struct xhci_hcd *xhci, + struct usb_device *udev, + struct usb_endpoint_descriptor *desc) +{ + unsigned long long timeout_ns; + + if (xhci->quirks & XHCI_INTEL_HOST) + timeout_ns = xhci_calculate_intel_u1_timeout(udev, desc); + else + timeout_ns = udev->u1_params.sel; + + /* The U1 timeout is encoded in 1us intervals. + * Don't return a timeout of zero, because that's USB3_LPM_DISABLED. + */ if (timeout_ns == USB3_LPM_DISABLED) - timeout_ns++; + timeout_ns = 1; + else + timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 1000); /* If the necessary timeout value is bigger than what we can set in the * USB 3.0 hub, we have to disable hub-initiated U1. @@ -4345,14 +4362,14 @@ static u16 xhci_calculate_intel_u1_timeout(struct usb_device *udev, return xhci_get_timeout_no_hub_lpm(udev, USB3_LPM_U1); } -/* Returns the hub-encoded U2 timeout value. - * The U2 timeout should be the maximum of: +/* The U2 timeout should be the maximum of: * - 10 ms (to avoid the bandwidth impact on the scheduler) * - largest bInterval of any active periodic endpoint (to avoid going * into lower power link states between intervals). * - the U2 Exit Latency of the device */ -static u16 xhci_calculate_intel_u2_timeout(struct usb_device *udev, +static unsigned long long xhci_calculate_intel_u2_timeout( + struct usb_device *udev, struct usb_endpoint_descriptor *desc) { unsigned long long timeout_ns; @@ -4368,6 +4385,21 @@ static u16 xhci_calculate_intel_u2_timeout(struct usb_device *udev, if (u2_del_ns > timeout_ns) timeout_ns = u2_del_ns; + return timeout_ns; +} + +/* Returns the hub-encoded U2 timeout value. */ +static u16 xhci_calculate_u2_timeout(struct xhci_hcd *xhci, + struct usb_device *udev, + struct usb_endpoint_descriptor *desc) +{ + unsigned long long timeout_ns; + + if (xhci->quirks & XHCI_INTEL_HOST) + timeout_ns = xhci_calculate_intel_u2_timeout(udev, desc); + else + timeout_ns = udev->u2_params.sel; + /* The U2 timeout is encoded in 256us intervals */ timeout_ns = DIV_ROUND_UP_ULL(timeout_ns, 256 * 1000); /* If the necessary timeout value is bigger than what we can set in the @@ -4386,13 +4418,10 @@ static u16 xhci_call_host_update_timeout_for_endpoint(struct xhci_hcd *xhci, enum usb3_link_state state, u16 *timeout) { - if (state == USB3_LPM_U1) { - if (xhci->quirks & XHCI_INTEL_HOST) - return xhci_calculate_intel_u1_timeout(udev, desc); - } else { - if (xhci->quirks & XHCI_INTEL_HOST) - return xhci_calculate_intel_u2_timeout(udev, desc); - } + if (state == USB3_LPM_U1) + return xhci_calculate_u1_timeout(xhci, udev, desc); + else if (state == USB3_LPM_U2) + return xhci_calculate_u2_timeout(xhci, udev, desc); return USB3_LPM_DISABLED; } @@ -4469,7 +4498,8 @@ static int xhci_check_tier_policy(struct xhci_hcd *xhci, { if (xhci->quirks & XHCI_INTEL_HOST) return xhci_check_intel_tier_policy(udev, state); - return -EINVAL; + else + return 0; } /* Returns the U1 or U2 timeout that should be enabled. -- 2.20.1