diff options
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index d7b9f484d..385f9f5d6 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -175,6 +175,16 @@ int xhci_reset(struct xhci_hcd *xhci) command |= CMD_RESET; writel(command, &xhci->op_regs->command); + /* Existing Intel xHCI controllers require a delay of 1 mS, + * after setting the CMD_RESET bit, and before accessing any + * HC registers. This allows the HC to complete the + * reset operation and be ready for HC register access. + * Without this delay, the subsequent HC register access, + * may result in a system hang very rarely. + */ + if (xhci->quirks & XHCI_INTEL_HOST) + udelay(1000); + ret = xhci_handshake(&xhci->op_regs->command, CMD_RESET, 0, 10 * 1000 * 1000); if (ret) @@ -3117,7 +3127,7 @@ static u32 xhci_calculate_no_streams_bitmask(struct xhci_hcd *xhci, } /* - * The USB device drivers use this function (though the HCD interface in USB + * The USB device drivers use this function (through the HCD interface in USB * core) to prepare a set of bulk endpoints to use streams. Streams are used to * coordinate mass storage command queueing across multiple endpoints (basically * a stream ID == a task ID). @@ -4681,7 +4691,6 @@ int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd, { struct xhci_hcd *xhci; u16 mel; - int ret; xhci = hcd_to_xhci(hcd); if (!xhci || !(xhci->quirks & XHCI_LPM_SUPPORT) || @@ -4689,10 +4698,7 @@ int xhci_disable_usb3_lpm_timeout(struct usb_hcd *hcd, return 0; mel = calculate_max_exit_latency(udev, state, USB3_LPM_DISABLED); - ret = xhci_change_max_exit_latency(xhci, udev, mel); - if (ret) - return ret; - return 0; + return xhci_change_max_exit_latency(xhci, udev, mel); } #else /* CONFIG_PM */ |