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    • Ben Widawsky's avatar
      drm/i915: Disable GGTT PTEs on GEN6+ suspend · 828c7908
      Ben Widawsky authored 
      Once the machine gets to a certain point in the suspend process, we
expect the GPU to be idle. If it is not, we might corrupt memory.
Empirically (with an early version of this patch) we have seen this is
not the case. We cannot currently explain why the latent GPU writes
occur.

In the technical sense, this patch is a workaround in that we have an
issue we can't explain, and the patch indirectly solves the issue.
However, it's really better than a workaround because we understand why
it works, and it really should be a safe thing to do in all cases.

The noticeable effect other than the debug messages would be an increase
in the suspend time. I have not measure how expensive it actually is.

I think it would be good to spend further time to root cause why we're
seeing these latent writes, but it shouldn't preclude preventing the
fallout.

NOTE: It should be safe (and makes some sense IMO) to also keep the
VALID bit unset on resume when we clear_range(). I've opted not to do
this as properly clearing those bits at some later point would be extra
work.

v2: Fix bugzilla link

Bugzilla: http://bugs.freedesktop.org/show_bug.cgi?id=65496
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=59321


Tested-by: default avatarTakashi Iwai <tiwai@suse.de>
Tested-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: default avatarBen Widawsky <ben@bwidawsk.net>
Tested-By: default avatarTodd Previte <tprevite@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      828c7908
    • Ben Widawsky's avatar
      drm/i915: Make PTE valid encoding optional · b35b380e
      Ben Widawsky authored 
      

We need this to work around a corruption when the boot kernel image
loads the hibernated kernel image from swap on Haswell systems -
somehow not everything is properly shut off.

This is just the prep work, the next patch will implement the actual
workaround.

Signed-off-by: default avatarBen Widawsky <ben@bwidawsk.net>
[danvet: Add a commit message suitable for -fixes and add cc: stable]
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
      b35b380e
    • Mark Brown's avatar
      Merge remote-tracking branch 'asoc/fix/tlv320aic3x' into asoc-linus · 40f89896
      Mark Brown authored
      40f89896
    • Mark Brown's avatar
      Merge remote-tracking branch 'asoc/fix/rcar' into asoc-linus · 2a5e9dab
      Mark Brown authored
      2a5e9dab
    • Mark Brown's avatar
      Merge remote-tracking branch 'asoc/fix/pcm1792a' into asoc-linus · d55f0691
      Mark Brown authored
      d55f0691
    • Mark Brown's avatar
      Merge remote-tracking branch 'asoc/fix/pcm1681' into asoc-linus · 3b8c006b
      Mark Brown authored
      3b8c006b
    • Mark Brown's avatar
      Merge remote-tracking branch 'asoc/fix/omap' into asoc-linus · d6ed3153
      Mark Brown authored
      d6ed3153
    • Mark Brown's avatar
      Merge remote-tracking branch 'asoc/fix/fsl' into asoc-linus · 762f9b18
      Mark Brown authored
      762f9b18
    • Nikolai Kondrashov's avatar
      HID: Fix unit exponent parsing again · ad0e669b
      Nikolai Kondrashov authored 
      Revert some changes done in 77463838

.

Revert all changes done in hidinput_calc_abs_res as it mistakingly used
"Unit" item exponent nibbles to affect resolution value. This wasn't
breaking resolution calculation of relevant axes of any existing
devices, though, as they have only one dimension to their units and thus
1 in the corresponding nible.

Revert to reading "Unit Exponent" item value as a signed integer in
hid_parser_global to fix reading specification-complying values. This
fixes resolution calculation of devices complying to the HID standard,
including Huion, KYE, Waltop and UC-Logic graphics tablets which have
their report descriptors fixed by the drivers.

Explanations follow.

There are two "unit exponents" in HID specification and it is important
not to mix them. One is the global "Unit Exponent" item and another is
nibble values in the global "Unit" item. See 6.2.2.7 Global Items.

The "Unit Exponent" value is just a signed integer and is used to scale
the integer resolution unit values, so fractions can be expressed.

The nibbles of "Unit" value are used to select the unit system (nibble
0), and presence of a particular basic unit type in the unit formula and
its *exponent* (or power, nibbles 1-6). And yes, the latter is in two
complement and zero means absence of the unit type.

Taking the representation example of (integer) joules from the
specification:

[mass(grams)][length(centimeters)^2][time(seconds)^-2] * 10^-7

the "Unit Exponent" would be -7 (or 0xF9, if stored as a byte) and the
"Unit" value would be 0xE121, signifying:

Nibble  Part        Value   Meaning
-----   ----        -----   -------
0       System      1       SI Linear
1       Length      2       Centimeters^2
2       Mass        1       Grams
3       Time        -2      Seconds^-2

To give the resolution in e.g. hundredth of joules the "Unit Exponent"
item value should have been -9.

See also the examples of "Unit" values for some common units in the same
chapter.

However, there is a common misunderstanding about the "Unit Exponent"
value encoding, where it is assumed to be stored the same as nibbles in
"Unit" item. This is most likely due to the specification being a bit
vague and overloading the term "unit exponent". This also was and still
is proliferated by the official "HID Descriptor Tool", which makes this
mistake and stores "Unit Exponent" as such. This format is also
mentioned in books such as "USB Complete" and in Microsoft's hardware
design guides.

As a result many devices currently on the market use this encoding and
so the driver should support them.

Signed-off-by: default avatarNikolai Kondrashov <spbnick@gmail.com>
Acked-by: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
      ad0e669b
    • Rafael J. Wysocki's avatar
      Merge branch 'acpi-fixes' · 981984cb
      Rafael J. Wysocki authored 
      * acpi-fixes:
  ACPI / PM: Drop two functions that are not used any more
  ATA / ACPI: remove power dependent device handling
  ACPI / power: Drop automaitc resume of power resource dependent devices
  ACPI: remove /proc/acpi/event from ACPI_BUTTON help
  ACPI / power: Release resource_lock after acpi_power_get_state() return error
      981984cb