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| author | Paolo Bonzini <pbonzini@redhat.com> | 2015-11-24 19:34:40 +0100 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-11-24 19:34:40 +0100 |
| commit | 8bd142c01648cdb33e9bcafa0448ba2c20ed814c (patch) | |
| tree | 9197c60d3f9d4036f38f281a183e94750ceea1d7 /drivers/usb/host/xhci.c | |
| parent | d792abacaf1a1a8dfea353fab699b97fa6251c2a (diff) | |
| parent | fbb4574ce9a37e15a9872860bf202f2be5bdf6c4 (diff) | |
Merge tag 'kvm-arm-for-v4.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master
KVM/ARM Fixes for v4.4-rc3.
Includes some timer fixes, properly unmapping PTEs, an errata fix, and two
tweaks to the EL2 panic code.
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 6e7dc6f93978..dfa44d3e8eee 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) |