PPP handles packet loss but does not work with out of order packets.
This change performs reordering of incoming data packets within a
sliding window of one second. Since sequence number is optional,
receiving a packet without it will drop all queued packets.
Currently the logic is triggered by incoming packets, so queued
packets have to wait till another packet is arrived. It is done for
simplicity since no additional locks or threads are required. For
reliable protocols, a retransmission will kick it. For unreliable
protocols, queued packets just seem like packet loss. Time-critical
protocols might be broken, but they never work with queueing anyway.
Signed-off-by: Chia-chi Yeh <chiachi@android.com>
This governor is designed for latency-sensitive workloads, such as
interactive user interfaces. The interactive governor aims to be
significantly more responsive to ramp CPU quickly up when CPU-intensive
activity begins.
Existing governors sample CPU load at a particular rate, typically
every X ms. This can lead to under-powering UI threads for the period of
time during which the user begins interacting with a previously-idle system
until the next sample period happens.
The 'interactive' governor uses a different approach. Instead of sampling
the CPU at a specified rate, the governor will check whether to scale the
CPU frequency up soon after coming out of idle. When the CPU comes out of
idle, a timer is configured to fire within 1-2 ticks. If the CPU is very
busy from exiting idle to when the timer fires then we assume the CPU is
underpowered and ramp to MAX speed.
If the CPU was not sufficiently busy to immediately ramp to MAX speed, then
the governor evaluates the CPU load since the last speed adjustment,
choosing the highest value between that longer-term load or the short-term
load since idle exit to determine the CPU speed to ramp to.
A realtime thread is used for scaling up, giving the remaining tasks the
CPU performance benefit, unlike existing governors which are more likely to
schedule rampup work to occur after your performance starved tasks have
completed.
The tuneables for this governor are:
/sys/devices/system/cpu/cpufreq/interactive/min_sample_time:
The minimum amount of time to spend at the current frequency before
ramping down. This is to ensure that the governor has seen enough
historic CPU load data to determine the appropriate workload.
Default is 80000 uS.
/sys/devices/system/cpu/cpufreq/interactive/go_maxspeed_load
The CPU load at which to ramp to max speed. Default is 85.
Change-Id: Ib2b362607c62f7c56d35f44a9ef3280f98c17585
Signed-off-by: Mike Chan <mike@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Bug: 3152864
Move the x86_64 idle notifiers originally by Andi Kleen and Venkatesh
Pallipadi to generic.
Change-Id: Idf29cda15be151f494ff245933c12462643388d5
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
This patch adds a notifier which can be used by subsystems that may
be interested in when a task has completely died and is about to
have it's last resource freed.
The Android lowmemory killer uses this to determine when a task
it has killed has finally given up its goods.
Signed-off-by: San Mehat <san@google.com>
Add wake_peer which is called before starting UART TX. The idea here
is to provide a mechanism where we can wakeup our peer before sending
data.
Change-Id: I42e0779b635f64ca99184b45d5b028de80197491
Signed-off-by: San Mehat <san@google.com>
net: Fix a bitmask in PPPoPNS and rename constants in PPPoPNS and PPPoLAC.
Signed-off-by: Chia-chi Yeh <chiachi@android.com>
net: Fix a potential deadlock while releasing PPPoLAC/PPPoPNS socket.
PPP driver guarantees that no thread will be executing start_xmit() after
returning from ppp_unregister_channel(). To achieve this, a spinlock (downl)
is used. In pppolac_release(), ppp_unregister_channel() is called after sk_udp
is locked. At the same time, another thread might be running in pppolac_xmit()
with downl. Thus a deadlock will occur if the thread tries to lock sk_udp.
The same situation might happen on sk_raw in pppopns_release().
Signed-off-by: Chia-chi Yeh <chiachi@android.com>
net: Force PPPoLAC and PPPoPNS to bind an interface before creating PPP channel.
It is common to manipulate the routing table after configuring PPP device.
Since both PPPoLAC and PPPoPNS run over IP, care must be taken to make sure
that there is no loop in the routing table.
Although this can be done by adding a host route, it might still cause
problems when the interface is down for some reason.
To solve this, this patch forces both drivers to bind an interface before
creating PPP channel, so the system will not re-route the tunneling sockets
to another interface when the original one is down. Another benefit is that
now the host route is no longer required, so there is no need to remove it
when PPP channel is closed.
Signed-off-by: Chia-chi Yeh <chiachi@android.com>
net: Avoid sleep-inside-spinlock in PPPoLAC and PPPoPNS.
Since recv() and xmit() are called with a spinlock held, routines which might
sleep cannot be used. This issue is solved by following changes:
Incoming packets are now processed in backlog handler, recv_core(), instead of
recv(). Since backlog handler is always executed with socket spinlock held, the
requirement of ppp_input() is still satisfied.
Outgoing packets are now processed in workqueue handler, xmit_core(), instead of
xmit(). Note that kernel_sendmsg() is no longer used to prevent touching dead
sockets.
In release(), lock_sock() and pppox_unbind_sock() ensure that no thread is in
recv_core() or xmit(). Then socket handlers are restored before release_sock(),
so no packets will leak in backlog queue.
Signed-off-by: Chia-chi Yeh <chiachi@android.com>
net: Fix msg_iovlen in PPPoLAC and PPPoPNS.
Although any positive value should work (which is always true in both drivers),
the correct value should be 1.
Signed-off-by: Chia-chi Yeh <chiachi@android.com>
There is no need to take a wakelock for delayed lazy disable
work, it will be cancelled in the suspend handler and force
disabled. Only take the wakelock when the detect work is
queued, and make sure to drop the wakelock if the work is
cancelled.
Change-Id: I1e507a5f98848954ea21d45e23b6192c3132a349
Signed-off-by: Colin Cross <ccross@android.com>
A card driver can now specify that the underlying bus should *not*
auto-resume with the rest of the system. This is useful for reducing resume
latency as well as saving power when the card driver is not using the
bus. In the future, we'll add support for manual suspend
Signed-off-by: San Mehat <san@google.com>
This is required to support chips which use SDIO for signaling/
communication but do not implement the various card enumeration registers
as required for full SD / SDIO cards.
mmc: sdio: Fix bug where we're freeing the CIS tables we never allocated when using EMBEDDED_SDIO
mmc: Add max_blksize to embedded SDIO data
Signed-off-by: San Mehat <san@google.com>
This driver allows userspace to receive notification when client
specified key combinations are pressed.
The client opens /dev/keychord and writes a list of keychords
for the driver to monitor.
The client then reads or polls /dev/keychord for notifications.
A client specified ID for the keychord is returned from read()
when a keychord press is detected.
Signed-off-by: Mike Lockwood <lockwood@android.com>
keychord: fix to build without CONFIG_PREEMPT
Change-Id: I911f13aeda4224b6fa57863bc7e8972fec8837fb
Add a platform device in the board file to specify a reset key-combo.
The first time the key-combo is detected a work function that syncs
the filesystems is scheduled. If all the keys are released and then
pressed again, it calls panic. Reboot on panic should be set for
this to work.
Change-Id: I9d54283ca1fba45e4b1ae1a407524cdda8171143
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Supports keyboard matrixces, direct inputs, direct outputs and axes connected to gpios.
Change-Id: I5e921e6e3a1cc169316ee3b665f4cc21b5735114
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Nick Pelly <npelly@google.com>
