diff options
| author | Kevin Hilman <khilman@linaro.org> | 2015-12-17 08:48:38 -0800 |
|---|---|---|
| committer | Kevin Hilman <khilman@linaro.org> | 2015-12-17 08:48:38 -0800 |
| commit | 906d9eadd3b6698fa6ceb9bcdf41da6aa56d0a24 (patch) | |
| tree | b258d06410e154ce58d9b0d16ffba0834ff2a1ac /drivers/usb/host/xhci.c | |
| parent | d3d3a134d75d28034b950bc0b6682ba0be976f37 (diff) | |
| parent | 9f41e6b222c4a04c7b46068df82842a6188b4a57 (diff) | |
Merge branch 'linux-linaro-lsk-v4.1' into linux-linaro-lsk-v4.1-rtlsk-v4.1-16.03-rtlsk-v4.1-16.02-rtlsk-v4.1-16.01-rtlsk-v4.1-15.12-rt
Diffstat (limited to 'drivers/usb/host/xhci.c')
| -rw-r--r-- | drivers/usb/host/xhci.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index 26f62b2b33f8..1e6d7579709e 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) |