diff options
| author | Gary S. Robertson <gary.robertson@linaro.org> | 2016-01-20 15:45:29 -0600 |
|---|---|---|
| committer | Gary S. Robertson <gary.robertson@linaro.org> | 2016-01-20 15:45:29 -0600 |
| commit | 1d10e9e61dedad92bcf380a421d08f021e62ff1b (patch) | |
| tree | 8e7641caa0710f4eba713a7f25de5eb314720993 /drivers/usb/host/xhci.c | |
| parent | d532db8c82faef41ad16e6db7a8459aa21f4a822 (diff) | |
| parent | 9f41e6b222c4a04c7b46068df82842a6188b4a57 (diff) | |
Merge tag 'lsk-v4.1-15.12' of http://git.linaro.org/kernel/linux-linaro-stable into linux-linaro-lng-v4.1linux-lng-4.1.14-2016.03linux-lng-4.1.14-2016.02linux-lng-4.1.14-2016.01linux-linaro-lng-v4.1
LSK 15.12 v4.1
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) |