On Tue, Jul 31, 2012 at 05:48:38PM -0500, Alexis R. Cortes wrote:
> This patch is intended to work around a known issue on the
> SN65LVPE502CP USB3.0 re-driver that can delay the negotiation
> between a device and the host past the usual handshake timeout,
> and if that happens on the first insertion, the host controller
> port will enter in Compliance Mode as per xHCI Spec. The patch
> creates a timer which polls every 2 seconds the link state of each
> host controller's port (this by reading the PORTSC register) and
> recovers the port by issuing a Warm reset every time Compliance mode
> is detected.
>
> Signed-off-by: Alexis R. Cortes <alexis.cortes@xxxxxx>
> ---
> drivers/usb/host/xhci-hub.c | 27 ++++++++++++++
> drivers/usb/host/xhci.c | 81 +++++++++++++++++++++++++++++++++++++++++++
> drivers/usb/host/xhci.h | 6 +++
> 3 files changed, 114 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 7b01094..4ea498d 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -493,7 +493,19 @@ static void xhci_hub_report_link_state(u32 *status, u32 status_reg)
> * when this bit is set.
> */
> pls |= USB_PORT_STAT_CONNECTION;
> + } else {
> + /*
> + * If CAS bit isn't set but the Port is already at
> + * Compliance Mode, fake a connection so the USB core
> + * notices the Compliance state and resets the port.
> + * This resolves an issue generated by the SN65LVPE502CP
> + * in which sometimes the port enters compliance mode
> + * caused by a delay on the host-device negotiation.
> + */
> + if (pls == USB_SS_PORT_LS_COMP_MOD)
> + pls |= USB_PORT_STAT_CONNECTION;
> }
> +
> /* update status field */
> *status |= pls;
> }
> @@ -645,6 +657,21 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
> /* Update Port Link State for super speed ports*/
> if (hcd->speed == HCD_USB3) {
> xhci_hub_report_link_state(&status, temp);
> + /*
> + * Verify if all USB3 Ports Have entered U0. Delete compliance
> + * mode timer if so.
> + */
> + if (xhci->quirks & XHCI_COMP_MODE_QUIRK) {
> + if (xhci->port_status_u0 != ((1 << xhci->num_usb3_ports)-1)) {
> + if ((temp & PORT_PLS_MASK) == XDEV_U0)
> + xhci->port_status_u0 |= 1 << wIndex;
> + } else {
> + /* Deleting Compliance Mode Recovery Timer */
> + if (del_timer_sync(&xhci->comp_mode_recovery_timer))
> + xhci_dbg(xhci, "Compliance Mode Recovery Timer Deleted. "
> + "All USB3 ports have entered U0 at least once.\n");
You need to disable the quirk flag here now, right? Otherwise can't the
timer be deleted twice if the module is unloaded after this happens?
thanks,
greg k-h
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