linux-toradex.git/drivers, branch v3.10.57

cpufreq: ondemand: Change the calculation of target frequency

2014-10-09T19:18:43+00:00

commit dfa5bb622555d9da0df21b50f46ebdeef390041b upstream.

The ondemand governor calculates load in terms of frequency and
increases it only if load_freq is greater than up_threshold
multiplied by the current or average frequency.  This appears to
produce oscillations of frequency between min and max because,
for example, a relatively small load can easily saturate minimum
frequency and lead the CPU to the max.  Then, it will decrease
back to the min due to small load_freq.

Change the calculation method of load and target frequency on the
basis of the following two observations:

 - Load computation should not depend on the current or average
   measured frequency.  For example, absolute load of 80% at 100MHz
   is not necessarily equivalent to 8% at 1000MHz in the next
   sampling interval.

 - It should be possible to increase the target frequency to any
   value present in the frequency table proportional to the absolute
   load, rather than to the max only, so that:

   Target frequency = C * load

   where we take C = policy->cpuinfo.max_freq / 100.

Tested on Intel i7-3770 CPU @ 3.40GHz and on Quad core 1500MHz Krait.
Phoronix benchmark of Linux Kernel Compilation 3.1 test shows an
increase ~1.5% in performance. cpufreq_stats (time_in_state) shows
that middle frequencies are used more, with this patch.  Highest
and lowest frequencies were used less by ~9%.

[rjw: We have run multiple other tests on kernels with this
 change applied and in the vast majority of cases it turns out
 that the resulting performance improvement also leads to reduced
 consumption of energy.  The change is additionally justified by
 the overall simplification of the code in question.]

Signed-off-by: Stratos Karafotis 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Cc: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix wrong time unit conversion

2014-10-09T19:18:43+00:00

commit a857c0b9e24e39fe5be82451b65377795f9538d8 upstream.

The time spent by a CPU under a given frequency is stored in jiffies unit
in the cpu var cpufreq_stats_table->time_in_state[i], i being the index of
the frequency.

This is what is displayed in the following file on the right column:

     cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
     2301000 19835820
     2300000 3172
     [...]

Now cpufreq converts this jiffies unit delta to clock_t before returning it
to the user as in the above file. And that conversion is achieved using the API
cputime64_to_clock_t().

Although it accidentally works on traditional tick based cputime accounting, where
cputime_t maps directly to jiffies, it doesn't work with other types of cputime
accounting such as CONFIG_VIRT_CPU_ACCOUNTING_* where cputime_t can map to nsecs
or any granularity preffered by the architecture.

For example we get a buggy zero delta on full dyntick configurations:

     cat /sys/devices/system/cpu/cpuX/cpufreq/stats/time_in_state
     2301000 0
     2300000 0
     [...]

Fix this with using the proper jiffies_64_t to clock_t conversion.

Reported-and-tested-by: Carsten Emde 
Signed-off-by: Andreas Schwab 
Signed-off-by: Frederic Weisbecker 
Acked-by: Paul E. McKenney 
Signed-off-by: Rafael J. Wysocki 
Cc: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

drbd: fix regression 'out of mem, failed to invoke fence-peer helper'

2014-10-09T19:18:43+00:00

commit bbc1c5e8ad6dfebf9d13b8a4ccdf66c92913eac9 upstream.

Since linux kernel 3.13, kthread_run() internally uses
wait_for_completion_killable().  We sometimes may use kthread_run()
while we still have a signal pending, which we used to kick our threads
out of potentially blocking network functions, causing kthread_run() to
mistake that as a new fatal signal and fail.

Fix: flush_signals() before kthread_run().

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Greg Kroah-Hartman

md/raid5: disable 'DISCARD' by default due to safety concerns.

2014-10-09T19:18:43+00:00

commit 8e0e99ba64c7ba46133a7c8a3e3f7de01f23bd93 upstream.

It has come to my attention (thanks Martin) that 'discard_zeroes_data'
is only a hint.  Some devices in some cases don't do what it
says on the label.

The use of DISCARD in RAID5 depends on reads from discarded regions
being predictably zero.  If a write to a previously discarded region
performs a read-modify-write cycle it assumes that the parity block
was consistent with the data blocks.  If all were zero, this would
be the case.  If some are and some aren't this would not be the case.
This could lead to data corruption after a device failure when
data needs to be reconstructed from the parity.

As we cannot trust 'discard_zeroes_data', ignore it by default
and so disallow DISCARD on all raid4/5/6 arrays.

As many devices are trustworthy, and as there are benefits to using
DISCARD, add a module parameter to over-ride this caution and cause
DISCARD to work if discard_zeroes_data is set.

If a site want to enable DISCARD on some arrays but not on others they
should select DISCARD support at the filesystem level, and set the
raid456 module parameter.
    raid456.devices_handle_discard_safely=Y

As this is a data-safety issue, I believe this patch is suitable for
-stable.
DISCARD support for RAID456 was added in 3.7

Cc: Shaohua Li 
Cc: "Martin K. Petersen" 
Cc: Mike Snitzer 
Cc: Heinz Mauelshagen 
Acked-by: Martin K. Petersen 
Acked-by: Mike Snitzer 
Fixes: 620125f2bf8ff0c4969b79653b54d7bcc9d40637
Signed-off-by: NeilBrown 
[bwh: Backported to 3.10: adjust context]
Signed-off-by: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

media: vb2: fix VBI/poll regression

2014-10-09T19:18:42+00:00

commit 58d75f4b1ce26324b4d809b18f94819843a98731 upstream.

The recent conversion of saa7134 to vb2 unconvered a poll() bug that
broke the teletext applications alevt and mtt. These applications
expect that calling poll() without having called VIDIOC_STREAMON will
cause poll() to return POLLERR. That did not happen in vb2.

This patch fixes that behavior. It also fixes what should happen when
poll() is called when STREAMON is called but no buffers have been
queued. In that case poll() will also return POLLERR, but only for
capture queues since output queues will always return POLLOUT
anyway in that situation.

This brings the vb2 behavior in line with the old videobuf behavior.

Signed-off-by: Hans Verkuil 
Acked-by: Laurent Pinchart 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

serial: 8250_dma: check the result of TX buffer mapping

2014-10-05T21:54:15+00:00

commit d4089a332883ad969700aac5dd4dd5f1c4fee825 upstream.

Using dma_mapping_error() to make sure the mapping did not
fail.

Signed-off-by: Heikki Krogerus 
Cc: "Petallo, MauriceX R" 
Signed-off-by: Greg Kroah-Hartman

md/raid1: fix_read_error should act on all non-faulty devices.

2014-10-05T21:54:14+00:00

commit b8cb6b4c121e1bf1963c16ed69e7adcb1bc301cd upstream.

If a devices is being recovered it is not InSync and is not Faulty.

If a read error is experienced on that device, fix_read_error()
will be called, but it ignores non-InSync devices.  So it will
neither fix the error nor fail the device.

It is incorrect that fix_read_error() ignores non-InSync devices.
It should only ignore Faulty devices.  So fix it.

This became a bug when we allowed reading from a device that was being
recovered.  It is suitable for any subsequent -stable kernel.

Fixes: da8840a747c0dbf49506ec906757a6b87b9741e9
Reported-by: Alexander Lyakas 
Tested-by: Alexander Lyakas 
Signed-off-by: NeilBrown 
Signed-off-by: Greg Kroah-Hartman

media: cx18: fix kernel oops with tda8290 tuner

2014-10-05T21:54:14+00:00

commit 6a03dc92cc2edfa2257502557b9f714893987383 upstream.

This was caused by an uninitialized setup.config field.

Based on a suggestion from Devin Heitmueller.

Signed-off-by: Hans Verkuil 
Thanks-to: Devin Heitmueller 
Reported-by: Scott Robinson 
Tested-by: Hans Verkuil 
Signed-off-by: Mauro Carvalho Chehab 
Signed-off-by: Greg Kroah-Hartman

usb: dwc3: core: fix ordering for PHY suspend

2014-10-05T21:54:13+00:00

commit dc99f16f076559235c92d3eb66d03d1310faea08 upstream.

We can't suspend the PHYs before dwc3_core_exit_mode()
has been called, that's because the host and/or device
sides might still need to communicate with the far end
link partner.

Fixes: 8ba007a (usb: dwc3: core: enable the USB2 and USB3 phy in probe)
Suggested-by: Alan Stern 
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman

usb: dwc3: core: fix order of PM runtime calls

2014-10-05T21:54:13+00:00

commit fed33afce0eda44a46ae24d93aec1b5198c0bac4 upstream.

Currently, we disable pm_runtime before all register
accesses are done, this is dangerous and might lead
to abort exceptions due to the driver trying to access
a register which is clocked by a clock which was long
gated.

Fix that by moving pm_runtime_put_sync() and pm_runtime_disable()
as the last thing we do before returning from our ->remove()
method.

Fixes: 72246da (usb: Introduce DesignWare USB3 DRD Driver)
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman