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author | Mathias Nyman <mathias.nyman@linux.intel.com> | 2018-12-05 14:22:39 +0200 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-13 09:20:29 +0100 |
commit | d65afda688f3aae97da58ce401f65e76f659cfa8 (patch) | |
tree | 4994c7c0ecc8056116e96538c4a76714adcb34ff /Documentation/xillybus.txt | |
parent | 1f7170700fb2e262393ee948cf9c6cdc72717fc3 (diff) |
xhci: Prevent U1/U2 link pm states if exit latency is too long
commit 0472bf06c6fd33c1a18aaead4c8f91e5a03d8d7b upstream.
Don't allow USB3 U1 or U2 if the latency to wake up from the U-state
reaches the service interval for a periodic endpoint.
This is according to xhci 1.1 specification section 4.23.5.2 extra note:
"Software shall ensure that a device is prevented from entering a U-state
where its worst case exit latency approaches the ESIT."
Allowing too long exit latencies for periodic endpoint confuses xHC
internal scheduling, and new devices may fail to enumerate with a
"Not enough bandwidth for new device state" error from the host.
Cc: <stable@vger.kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/xillybus.txt')
0 files changed, 0 insertions, 0 deletions