linux-stable.git/Documentation, branch linux-4.6.y

Revert "cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency"

2016-08-16T07:33:19+00:00

commit da7d3abe1c9e5ebac2cf86f97e9e89888a5e2094 upstream.

This reverts commit 790d849bf811a8ab5d4cd2cce0f6fda92f6aebf2.

Using a v4.7-rc7 kernel on a HP ProLiant triggered following messages

 pcc-cpufreq: (v1.10.00) driver loaded with frequency limits: 1200 MHz, 2800 MHz
 cpufreq: ondemand governor failed, too long transition latency of HW, fallback to performance governor

The last line was shown for each CPU in the system.
Testing v4.5 (where commit 790d849b was integrated) triggered
similar messages. Same behaviour on a 2nd HP Proliant system.

So commit 790d849bf (cpufreq: pcc-cpufreq: update default value of
cpuinfo_transition_latency) causes the system to use performance
governor which, I guess, was not the intention of the patch.

Enabling debug output in pcc-cpufreq provides following verbose output:

 pcc-cpufreq: (v1.10.00) driver loaded with frequency limits: 1200 MHz, 2800 MHz
 pcc_get_offset: for CPU 0: pcc_cpu_data input_offset: 0x44, pcc_cpu_data output_offset: 0x48
 init: policy->max is 2800000, policy->min is 1200000
 get: get_freq for CPU 0
 get: SUCCESS: (virtual) output_offset for cpu 0 is 0xffffc9000d7c0048, contains a value of: 0xff06. Speed is: 168000 MHz
 cpufreq: ondemand governor failed, too long transition latency of HW, fallback to performance governor
 target: CPU 0 should go to target freq: 2800000 (virtual) input_offset is 0xffffc9000d7c0044
 target: was SUCCESSFUL for cpu 0

I am asking to revert 790d849bf to re-enable usage of ondemand
governor with pcc-cpufreq.

Fixes: 790d849bf (cpufreq: pcc-cpufreq: update default value of cpuinfo_transition_latency)
Signed-off-by: Andreas Herrmann 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

x86/pat: Document the PAT initialization sequence

2016-08-16T07:33:18+00:00

commit b6350c21cfe8aa9d65e189509a23c0ea4b8362c2 upstream.

Update PAT documentation to describe how PAT is initialized under
various configurations.

Signed-off-by: Toshi Kani 
Reviewed-by: Thomas Gleixner 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Borislav Petkov 
Cc: Brian Gerst 
Cc: Denys Vlasenko 
Cc: H. Peter Anvin 
Cc: Juergen Gross 
Cc: Linus Torvalds 
Cc: Luis R. Rodriguez 
Cc: Peter Zijlstra 
Cc: Toshi Kani 
Cc: elliott@hpe.com
Cc: konrad.wilk@oracle.com
Cc: paul.gortmaker@windriver.com
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1458769323-24491-8-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

scsi: fix race between simultaneous decrements of ->host_failed

2016-07-27T15:42:24+00:00

commit 72d8c36ec364c82bf1bf0c64dfa1041cfaf139f7 upstream.

sas_ata_strategy_handler() adds the works of the ata error handler to
system_unbound_wq. This workqueue asynchronously runs work items, so the
ata error handler will be performed concurrently on different CPUs. In
this case, ->host_failed will be decreased simultaneously in
scsi_eh_finish_cmd() on different CPUs, and become abnormal.

It will lead to permanently inequality between ->host_failed and
->host_busy, and scsi error handler thread won't start running. IO
errors after that won't be handled.

Since all scmds must have been handled in the strategy handler, just
remove the decrement in scsi_eh_finish_cmd() and zero ->host_busy after
the strategy handler to fix this race.

Fixes: 50824d6c5657 ("[SCSI] libsas: async ata-eh")
Signed-off-by: Wei Fang 
Reviewed-by: James Bottomley 
Signed-off-by: Martin K. Petersen 
Signed-off-by: Greg Kroah-Hartman

iio: proximity: as3935: correct IIO_CHAN_INFO_RAW output

2016-07-27T15:42:20+00:00

commit 5138806f16c74c7cb8ac3e408a859c79eb7c9567 upstream.

IIO_CHAN_INFO_RAW was returning processed data which was incorrect.
This also adds the IIO_CHAN_INFO_SCALE value to convert to a processed value.

Signed-off-by: Matt Ranostay 
Signed-off-by: Jonathan Cameron 
Signed-off-by: Greg Kroah-Hartman

drm: Add helper for DP++ adaptors

2016-06-08T01:23:41+00:00

commit b3daa5ef52c26acd7432c787989bd92d48070c76 upstream.

Add a helper which aids in the identification of DP dual mode
(aka. DP++) adaptors. There are several types of adaptors
specified: type 1 DVI, type 1 HDMI, type 2 DVI, type 2 HDMI

Type 1 adaptors have a max TMDS clock limit of 165MHz, type 2 adaptors
may go as high as 300MHz and they provide a register informing the
source device what the actual limit is. Supposedly also type 1 adaptors
may optionally implement this register. This TMDS clock limit is the
main reason why we need to identify these adaptors.

Type 1 adaptors provide access to their internal registers and the sink
DDC bus through I2C. Type 2 adaptors provide this access both via I2C
and I2C-over-AUX. A type 2 source device may choose to implement either
of these methods. If a source device implements the I2C-over-AUX
method, then the driver will obviously need specific support for such
adaptors since the port is driven like an HDMI port, but DDC
communication happes over the AUX channel.

This helper should be enough to identify the adaptor type (some
type 1 DVI adaptors may be a slight exception) and the maximum TMDS
clock limit. Another feature that may be available is control over
the TMDS output buffers on the adaptor, possibly allowing for some
power saving when the TMDS link is down.

Other user controllable features that may be available in the adaptors
are downstream i2c bus speed control when using i2c-over-aux, and
some control over the CEC pin. I chose not to provide any helper
functions for those since I have no use for them in i915 at this time.
The rest of the registers in the adaptor are mostly just information,
eg. IEEE OUI, hardware and firmware revision, etc.

v2: Pass adaptor type to helper functions to ease driver implementation
    Fix a bunch of typoes (Paulo)
    Add DRM_DP_DUAL_MODE_UNKNOWN for the case where we don't (yet) know
    the type (Paulo)
    Reject 0x00 and 0xff DP_DUAL_MODE_MAX_TMDS_CLOCK values (Paulo)
    Adjust drm_dp_dual_mode_detect() type2 vs. type1 detection to
    ease future LSPCON enabling
    Remove the unused DP_DUAL_MODE_LAST_RESERVED define
v3: Fix kernel doc function argument descriptions (Jani)
    s/NONE/UNKNOWN/ in drm_dp_dual_mode_detect() docs
    Add kernel doc for enum drm_dp_dual_mode_type
    Actually build the docs
    Fix more typoes
v4: Adjust code indentation of type2 adaptor detection (Shashank)
    Add debug messages for failurs cases (Shashank)
v5: EXPORT_SYMBOL(drm_dp_dual_mode_read) (Paulo)

Cc: Tore Anderson 
Cc: Paulo Zanoni 
Cc: Shashank Sharma 
Cc: Daniel Vetter 
Cc: Shashank Sharma 
Signed-off-by: Ville Syrjälä 
Reviewed-by: Shashank Sharma  (v4)
Link: http://patchwork.freedesktop.org/patch/msgid/1462542412-25533-1-git-send-email-ville.syrjala@linux.intel.com
(cherry picked from commit ede53344dbfd1dd43bfd73eb6af743d37c56a7c3)
Signed-off-by: Jani Nikula 
Signed-off-by: Greg Kroah-Hartman

ARM: dts: imx35: restore existing used clock enumeration

2016-06-08T01:23:35+00:00

commit 3397c2c45b1b6f54834dfeae30a73046f33ca943 upstream.

A new element got inserted into enum mx35_clks with commit 3713e3f5e927
("clk: imx35: define two clocks for rtc"). This insertion shifted most
nummerical clock assignments to a new nummerical value which in turn
rendered most hardcoded nummeric values in imx35.dtsi incorrect.

Restore the existing order by moving the newly introduced clock to the
end of the enum. Update the dts documentation accordingly.

Signed-off-by: Alexander Kurz 
Fixes: 3713e3f5e927 ("clk: imx35: define two clocks for rtc")
Signed-off-by: Shawn Guo 
Signed-off-by: Greg Kroah-Hartman

Fix OpenSSH pty regression on close

2016-06-01T19:18:03+00:00

commit 0f40fbbcc34e093255a2b2d70b6b0fb48c3f39aa upstream.

OpenSSH expects the (non-blocking) read() of pty master to return
EAGAIN only if it has received all of the slave-side output after
it has received SIGCHLD. This used to work on pre-3.12 kernels.

This fix effectively forces non-blocking read() and poll() to
block for parallel i/o to complete for all ttys. It also unwinds
these changes:

1) f8747d4a466ab2cafe56112c51b3379f9fdb7a12
   tty: Fix pty master read() after slave closes

2) 52bce7f8d4fc633c9a9d0646eef58ba6ae9a3b73
   pty, n_tty: Simplify input processing on final close

3) 1a48632ffed61352a7810ce089dc5a8bcd505a60
   pty: Fix input race when closing

Inspired by analysis and patch from Marc Aurele La France 

Reported-by: Volth 
Reported-by: Marc Aurele La France 
BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=52
BugLink: https://bugzilla.mindrot.org/show_bug.cgi?id=2492
Signed-off-by: Brian Bloniarz 
Reviewed-by: Peter Hurley 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'regmap-fix-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

2016-05-13T16:40:32+00:00

Pull regmap fixes from Mark Brown:
 "This is rather too late so it'd be completely understandable if you
  don't want to pull it at this point, I had thought I'd sent this
  earlier but it seems I didn't.  Everything has been in -next for some
  time now.

  The main set of fixes here are mopping up some more issues with MMIO,
  fixing handling of endianness configuration in DT (which just wasn't
  working at all) and cases where the register and value endianness are
  different.

  There is also a fix for bulk register reads on SPMI"

* tag 'regmap-fix-v4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: spmi: Fix regmap_spmi_ext_read in multi-byte case
  regmap: mmio: Explicitly say little endian is the defualt in the bus config
  regmap: mmio: Parse endianness definitions from DT
  regmap: Fix implicit inclusion of device.h
  regmap: mmio: Fix value endianness selection
  regmap: fix documentation to match code

Merge remote-tracking branches 'regmap/fix/be', 'regmap/fix/doc' and 'regmap/fix/spmi' into regmap-linus

2016-05-13T09:36:10+00:00

perf/core: Change the default paranoia level to 2

2016-05-10T00:57:12+00:00

Allowing unprivileged kernel profiling lets any user dump follow kernel
control flow and dump kernel registers.  This most likely allows trivial
kASLR bypassing, and it may allow other mischief as well.  (Off the top
of my head, the PERF_SAMPLE_REGS_INTR output during /dev/urandom reads
could be quite interesting.)

Signed-off-by: Andy Lutomirski 
Acked-by: Kees Cook 
Signed-off-by: Linus Torvalds