On Thu, Apr 24, 2014 at 11:01:58PM +0800, Mathias Nyman wrote:
> On 04/22/2014 07:27 AM, Pratyush Anand wrote:
> > 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 <pratyush.an...@st.com>
> > Tested-by: Aymen Bouattay <aymen.bouat...@st.com>
> > ---
> > 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 6cc58fe..f5ac76a 100644
> > --- a/drivers/usb/host/xhci.c
> > +++ b/drivers/usb/host/xhci.c
> > @@ -4140,8 +4140,7 @@ 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:
> > @@ -4149,7 +4148,8 @@ 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;
> > @@ -4181,11 +4181,28 @@ 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.
> > @@ -4197,14 +4214,14 @@ 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;
> > @@ -4220,6 +4237,21 @@ 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
> > @@ -4238,13 +4270,10 @@ 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
> > + return xhci_calculate_u2_timeout(xhci, udev, desc);
> >
> > return USB3_LPM_DISABLED;
>
> Tiny nitpick, but this last return doesn't do much here.
>
> either:
> if (state == USB3_LPM_U1)
> return xhci_calculate_u1..
>
> return xhci_calculate_u2...
>
> or then:
>
> if (state == USB3_LPM_U1)
> return xhci_claculate_u1...
> else if (state == USB3_LPM_U2) /* or just if (state == USB_LPM_U2) */
> return xhci_calculate_u2..
> return USB3_LPM_DISABLED
This seems better.. Will modify in next version.
Pratyush
>
> -Mathias
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