Here are some Link PM patches. I wanted to put them out for review
before I send them off to Greg.
The first patch allows LPM to remain enabled after a driver fails a
probe. If libusual was compiled into the kernel, without this patch,
LPM would remain disabled after libusual loaded for USB 3.0 hard drives.
The second patch "usb: Don't enable LPM if the exit latency is zero."
has already been tested by Don.
The third patch doesn't change the behavior of any USB 3.0 devices I
own, but I think (based on my understanding of the spec) that the
devices need to receive the Set SEL request before we allow the link to
go into U1 or U2.
The fourth patch is a trivial debugging correction.
There's a couple of link PM patches that I haven't included in this
patchset, since I can't confirm they actually fix link PM errors.
One is the patch to blacklist LPM if the U1/U2 device exit latencies are
the maximum values. I have one SD card reader that reports the max
values, and goes into U1 and U2, but occasionally starts to have I/O
errors. It's really random when it does have I/O errors, so I'm not
sure if the SD card is going bad, or the device is having Link PM
issues. When the SD card exhibits I/O errors on the USB 3.0 bus, it
often starts having I/O errors under EHCI. That points more towards an
SD card issue.
The other patch I haven't included is the patch to blacklist LPM support
for VIA USB 3.0 hubs. It turns out that the USB 3.0 bus analyzer I was
using introduces errors on U1 exit, and can cause the link to become
unstable. All three of my VIA USB 3.0 hubs happily go into and out of
U1/U2 without the analyzer in between.
Sarah Sharp
The following changes since commit ecefbd94b834fa32559d854646d777c56749ef1c:
Merge tag 'kvm-3.7-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm (2012-10-04 09:30:33 -0700)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci.git for-usb-linus-pending
for you to fetch changes up to 1510a1a2d0946b34422fe8816187f274a5086904:
usb: trival: Fix debugging units mistake. (2012-10-08 11:48:41 -0700)
----------------------------------------------------------------
Sarah Sharp (4):
USB: Enable LPM after a failed probe.
usb: Don't enable LPM if the exit latency is zero.
usb: Send Set SEL before enabling parent U1/U2 timeout.
usb: trival: Fix debugging units mistake.
drivers/usb/core/driver.c | 4 ++++
drivers/usb/core/hub.c | 36 +++++++++++++++++++++++-------------
2 files changed, 27 insertions(+), 13 deletions(-)
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