block: row-iosched idling triggered by readahead pages

In the current implementation idling is triggered only by request
insertion frequency. This heuristic is not very accurate and may hit
random requests that shouldn't trigger idling. This patch uses the
PG_readahead flag in struct page's flags, which indicates that the page
is part of a readahead window, to start idling upon dispatch of a request
associated with a readahead page.

The above readehead flag is used together with the existing
insertion-frequency trigger. The frequency timer will catch read requests
which are not part of a readahead window, but are still part of a
sequential stream (and therefore dispatched in small time intervals).

Change-Id: Icb7145199c007408de3f267645ccb842e051fd00
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
block: row: Remove warning massage from add_request

Regular priority queues is marked as "starved" if it skipped a dispatch
due to being empty. When a new request is added to a "starved" queue
it will be marked as urgent.
The removed WARN_ON was warning about an impossible case when a regular
priority (read) queue was marked as starved but wasn't empty. This is
a possible case due to the bellow:
If the device driver fetched a read request that is pending for
transmission and an URGENT request arrives, the fetched read will be
reinserted back to the scheduler. Its possible that the queue it will be
reinserted to was marked as "starved" in the meanwhile due to being empty.

CRs-fixed: 517800
Change-Id: Iaae642ea0ed9c817c41745b0e8ae2217cc684f0c
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
msm: cpufreq: Ensure cpufreq change happens on corresponding CPU

Checking the cpus_allowed mask of the current thread before changing the
frequency doesn't guarantee that the rest of the execution will continue on
the same CPU. The only way to guarantee this is to schedule a work on the
specific CPU and also prevent hotplug  of that CPU (already done by
existing code).

Change-Id: I51a02fcc777a47d3c16f2d83c47e96f2c59f7ae6
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
msm: kgsl: Reduce unnecessary calls to _wake

If the device is already ACTIVE do not call _wake.

Change-Id: I2ae3956eb1bbc0a8bc0f1c147547aeed601622aa
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>
msm: kgsl: Fix a missing semicolon in the KGSL IOMMU handler

in check_if_freed() a call to kgsl_get_memory_usage() was terminated with
a comma instead of a semicolon.  Through a quirk in a macro this somehow
managed to compile and function properly but that doesn't make it okay.

CRs-fixed: 497280
Change-Id: Ic0dedbadfdf901bbc68b7f8cefb231d08dd01a95
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
mm: pass readahead info down to the i/o scheduler

Some i/o schedulers (i.e. row-iosched, cfq-iosched) deploy an idling
algorithm in order to be better synced with the readahead algorithm.
Idling is a prediction algorithm for incoming read requests.

In this patch we mark pages which are part of a readahead window, by
setting a newly introduced flag. With this flag, the i/o scheduler can
identify a request which is associated with a readahead page. This
enables the i/o scheduler's idling mechanism to be en-sync with the
readahead mechanism and, in turn, can increase read throughput.

Change-Id: I0654f23315b6d19d71bcc9cc029c6b281a44b196
Signed-off-by: Lee Susman <lsusman@codeaurora.org>
msm: krait-regulator-pmic: Add krait-regulator-pmic driver

Read the register configurations of regulators in the gang and
bug if the gang is not setup correctly.

Importantly, fix the voltage overshoots observed during PFM-PWM
transitions by implementing the following steps.

PFM -> PWM
After the buck is set to PWM mode, wait 50uS and then set the PWM
current limit to 3.5A.

PWM -> PFM
After the buck is set to pfm mode, immediately lower the PWM current limit
to 2A (no delay required).

Change-Id: I15af09aaf8427e75253a4e12878ee1f0a1265454
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>

Conflicts:

	arch/arm/mach-msm/Makefile
msm: krait-regulator: switch mode on the same cpu

The driver currently runs LDO-BHS mode switches while possibly
running on a different CPU. The CPU for which the mode switch is
issued could be running its SPM sequence as a part of going in or
coming out of power collapse. The LDO-BHS switching executed from a
different CPU could race with the mode switches done in SPM sequence
leaving the CPU in a bad state.

Fix this by executing LDO-BHS mode switches on the target CPU. This
guarantees that the SPM sequence won't be running on that CPU while
changing modes.

CRs-Fixed: 523449
Change-Id: I863ce3bcd6dd9ba3155c4573071f01e7a020ef48
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
msm: krait-regulator: rename online to reg_en

The online variable is confusing, since it does not mean whether
the core is online or offline. It actually used to indicate whether
the regulator is enabled or disabled.
Change the variable name to indicate so.

Change-Id: I20c270162df57cf81c17e808d383880b5b2e4eef
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
msm: krait-regulator: fix race conditions in regulator enable/disable

The driver suffers from the following race conditions:
* when a core is being onlined and is in its PREPARE_UP stage regulator
enable for that core is called. This call may cause a switch between
ldo-bhs but since the core if not online yet and ldo-bhs calls are
strictly executed on the target cpu - this leads to smp function calls
to fail.
* before the core in onlined and after the PREPARE_UP stage there could
be another frequency change that causes a gang voltage change that in turn
causes this core to switch states. This too leads to failed smp function
calls since they are targeted towards offline core
* when a cpu is offlined but a DEAD notification is not sent a frequency
change on another core may cause a switch on this cpu. This also leads
to failed smp function calls on offline core.

Fix the above by forcing the core to BHS when it is in its transitory
phase and while it is offlined. In other words a core will switch to
bhs/ldo based on the voltage requests only between CPU_ONLINE and
CPU_DOWN_PREPARE notifications. A core can run on BHS if it
can run on LDO since LDO just acts as a voltage step down, the core
can run when fed higher voltage from BHS.

To do this add hooks to get cpu hotplug notifications in the driver and
appropriately force bhs or switch to ldo or bhs based on gang voltage.

CRs-Fixed: 529593
Change-Id: I7210f62072853ed6f807df2d78bc2144f67eaf31
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
msm: hotplug: remove code related to cpu_killed

Earlier the completion event cpu_killed was used to synchronize
notify to hot plug framework that the CPU is dead. But now it is
replaced with another completion event cpu_died and it is placed
in the hotplug framework itself. So there is no need for a
platform to implement a completion event.

But in msm platform driver the completion event related code
was not removed with the changes in hotplug framework. This
patch removes the unused code.

Change-Id: I4418e5e397821e39a7b6a6efa997c4a866e9b46b
Signed-off-by: Venkat Devarasetty <vdevaras@codeaurora.org>
msm: kgsl: Only turn on the idle timer when active_cnt is 0

Only turn on the idle timer when the GPU expected to be quiet.
If the idle timer is enabled while the GPU is busy, there is
a chance it might unnecessarily fire during heavy GPU activity
such as a compute job.

Additionally, rather than trying to NAP directly from
kgsl_active_count_put(), just trigger the idle check work.

All of this makes the idle check happen more consistently.

Change-Id: Ic0dedbad57846f1e7bf7820ec3152cd20598b448
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
msm: mdss: initialize pipe to NULL

Initialize the pipe pointer to NULL.
So that even if the selection of pipe from pipe-pool
fails, the function returns NULL instead of an
uninitialized value.

Change-Id: Ib04c0a983cba6ffe9532862bcaf516877e49746a
CRs-Fixed: 524466
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
msm: mdss: validate fb backlight inputs

Ensure backlight level is less than the max backlight
brightness and the backlight scaling factor is at most
1.

Change-Id: I424ed22af48ecae46371291fe88a114cf3fc7c31
CRs-Fixed: 516699
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
msm: mdss: Make vsync wait non-interruptible in video_wait4comp

Currently in MDSS driver, vsync wait is getting interrupted due
to which input buffer to RGB pipe is getting unmapped/freed even
when the pipe is still connected to LM0 resulting in IOMMU fault.
So, making the vsync wait non-interruptible fixes the issue.

CRs-Fixed: 510352
Change-Id: I16d157079cc943ddfddc27a5317fc26c4fee1f0b
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>
msm: mdss: Compensate for low VBP in MDP clock calculations

MDP latency is 4 lines with CAF and when the panel's vertical
Back porch value is lower than 4, the MDP clk rate needs to
be increased by 25% to compensate for the latency.

Change-Id: I732de52b4f5387d5c7992e893ea7cad5c6951811
Signed-off-by: Sree Sesha Aravind Vadrevu <svadrevu@codeaurora.org>
mdss: ppp: Correct ppp bw request

Integer overflow occurred in calculating ib, this value was then
given to bw request resulting in an invalid request.

Change-Id: I71c56ecb7b412a8343ac400295a97f00207316e2
Signed-off-by: Terence Hampson <thampson@codeaurora.org>
msm: mdss: hdmi-cec: bounds check cec frame size

Ensure that the frame size for the HDMI-CEC message
frame size doesn't exceed the maximum size when
reading message from userspace through sysfs interface.
This avoids potential overflow in cec send msg routine.

Change-Id: I891f23ed70ed5a6c0e3af1f47869effa079ffac8
CRs-Fixed: 520140
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
msm: mdss: hdmi: NUL-terminate spd data

NUL-terminate SPD Vendor name and SPD
Product description data stored in the
control structure of hdmi driver. This
avoids overflows in print messages and info
frames.

Change-Id: I0a0adcfad06625e4d7368d3c5cd0ec38f0e047d8
CRs-Fixed: 520148
Signed-off-by: Manoj Rao <manojraj@codeaurora.org>
msm: mdss: Avoid deadlock in interrupt handler

Reduce the locking scope in irq_dispatch so that
mdss_lock is not held when the irq_handler is dispatched.
The dispatched irq_handler will try to acquire mdp_lock but
another active process can already have mdp_lock and tries to
procure mdss_lock creating a deadlock situation. Not locking
with mdss_lock is acceptable as the calls will be synchronized
through mdp_lock from MDP clients.

CRs-Fixed: 528550
Change-Id: I586b7e00c046dd4081b4e838e62e0a0556f4c717
Signed-off-by: Jayant Shekhar <jshekhar@codeaurora.org>