There are 2 separate loops to resize cpu buffers that are online and
offline. Merge them to make the code look better.
Also change the name from update_completion to update_done to allow
shorter lines.
Link: http://lkml.kernel.org/r/1337372991-14783-1-git-send-email-vnagarnaik@google.com
Cc: Laurent Chavey <chavey@google.com>
Cc: Justin Teravest <teravest@google.com>
Cc: David Sharp <dhsharp@google.com>
Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add the Kconfig/Makefile stuff for the palmas regulator driver
Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Palmas has both Switched Mode (SMPS) and Linear (LDO) regulators in it.
This regulator driver allows software control of these regulators.
The regulators available on Palmas series chips vary depending on the muxing.
This is handled automatically in the driver by reading the mux info from OTP.
Signed-off-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
If the allfrag feature has been set on a host route (due to an ICMPv6
Packet Too Big received indicating a MTU of less than 1280), we hit a
very slow behavior in TCP stack, because all big packets are dropped and
only a retransmit timer is able to push one MSS frame every 200 ms.
One way to handle this is to disable GSO on the socket the first time a
super packet is dropped. Adding a specific dst_allfrag() in the fast
path is probably overkill since the dst_allfrag() case almost never
happen.
Result on netperf TCP_STREAM, one flow :
Before : 60 kbit/sec
After : 1.6 Gbit/sec
Reported-by: Tore Anderson <tore@fud.no>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Tore Anderson <tore@fud.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Update our reference driver to use netdev_alloc_frag() API instead of
the temporary custom allocator I introduced in commit 8d4057a938
(tg3: provide frags as skb head)
This removes the memory leak we had, since we could leak one page at
device dismantle.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Matt Carlson <mcarlson@broadcom.com>
Cc: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Call consume_skb() in place of kfree_skb() were appropriate.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Repeat pull of soc-core to bring in a bugfix.
* 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/renesas:
ARM: mach-shmobile: sh73a0: fixup PINT/IRQ16-IRQ31 irq number conflict
Mostly bool conversions, some inline removals and const additions.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We already unconditionally dereference 'sk' via lock_sock(sk) earlier
in this function, and our caller (sock_do_ioctl()) makes takes similar
liberties.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Quoting Tore Anderson from :
If the allfrag feature has been set on a host route (due to an ICMPv6
Packet Too Big received indicating a MTU of less than 1280),
TCP SYN/ACK packets to that destination appears to get an incorrect
TCP checksum. This in turn means they are thrown away as invalid.
In the case of an IPv4 client behind a link with a MTU of less than
1260, accessing an IPv6 server through a stateless translator,
this means that the client can only download a single large file
from the server, because once it is in the server's routing cache
with the allfrag feature set, new TCP connections can no longer
be established.
</endquote>
It appears ip6_fragment() doesn't handle CHECKSUM_PARTIAL properly.
As network drivers are not prepared to fetch correct transport header, a
safe fix is to call skb_checksum_help() before fragmenting packet.
Reported-by: Tore Anderson <tore@fud.no>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Tore Anderson <tore@fud.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move blocks of code around to avoid function prototypes.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce and use a debug macro to test and print.
Convert printks to pr_<level>.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Just some stylings.
Use #include <linux... not #include <asm...
Convert a test and print to a printk_once.
Combine an "if (foo) { if (bar) {" to single "if (foo && bar) {"
to save an indent level.
Convert single line "if (foo) bar;" to multiple lines.
Move some braces.
Align some long lines a bit better.
Long lines and printks with KERN_ checkpatch complaints
still exist.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Neaten the comments and reflow the code without
changing anything other than whitespace.
git diff -w shows just comment neatening and a few
line removals.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the relocs tool throws an error, let the error message say if it
is an absolute or relative symbol. This should make it a lot more
clear what action the programmer needs to take and should help us find
the reason if additional symbol bugs show up.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
GNU ld 2.22.52.0.1 has a bug that it blindly changes symbols from
section-relative to absolute if they are in a section of zero length.
This turns the symbols __init_begin and __init_end into absolute
symbols. Let the relocs program know that those should be treated as
relative symbols.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: H.J. Lu <hjl.tools@gmail.com>
Cc: <stable@vger.kernel.org>
Cc: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
A new option is added to the relocs tool called '--realmode'.
This option causes the generation of 16-bit segment relocations
and 32-bit linear relocations for the real-mode code. When
the real-mode code is moved to the low-memory during kernel
initialization, these relocation entries can be used to
relocate the code properly.
In the assembly code 16-bit segment relocations must be relative
to the 'real_mode_seg' absolute symbol. Linear relocations must be
relative to a symbol prefixed with 'pa_'.
16-bit segment relocation is used to load cs:ip in 16-bit code.
Linear relocations are used in the 32-bit code for relocatable
data references. They are declared in the linker script of the
real-mode code.
The relocs tool is moved to arch/x86/tools/relocs.c, and added new
target archscripts that can be used to build scripts needed building
an architecture. be compiled before building the arch/x86 tree.
[ hpa: accelerating this because it detects invalid absolute
relocations, a serious bug in binutils 2.22.52.0.x which currently
produces bad kernels. ]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1336501366-28617-2-git-send-email-jarkko.sakkinen@intel.com
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org>
We need to use a different loop index for mlx4_counter_alloc() and for
device_create_file() iterations: the mlx4_counter_alloc() loop index
is used in the error flow to free counters.
If the same loop index is used for device_create_file() and, say, the
device_create_file() loop fails on the first iteration, the allocated
counters will not be freed.
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This patch removes two unused variables that are
defined in the _MINI_ADAPTER struct.
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch removes the following warning: "Use of
volatile is usually wrong: see
Documentation/volatile-considered-harmful.txt".
There were two variables defined in this manner.
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch fixes the following warning reported
by checkpatch.pl: "WARNING: __packed is preferred
over __attribute__((packed))".
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch correctly formats all comments as reported
by checkpatch.pl.
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch resolves all whitespace issues as reported
by checkpatch.pl.
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch cuddles braces as reported
by checkpatch.pl.
Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removed TPCI200_SHORTNAME. For the pr_* the name of the module is already
included due to pr_fmt declaration.
In other cases, KBUILD_MODNAME is used instead.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Removed board_name and bus_name fields from struct ipack_device that are
completely useless.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It adds and removes some fields in the struct ipack_device and
ipack_bus_device to make it cleaner.
The API has change to group all the operations on these structures inside
of the ipack driver.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1. Change the return type from int to void
All the detach functions, except for the comedi usb drivers, simply
return success (0). Plus, the return code is never checked in the
comedi core.
The comedi usb drivers do return error codes but the conditions can
never happen.
The first check is:
if (!dev)
return -EFAULT;
This checks that the passed comedi_device pointer is valid. The detach
function itself is called using this pointer so it MUST always be valid
or there is a bug in the core:
if (dev->driver)
dev->driver->detach(dev);
And the second check:
usb = dev->private;
if (!usb)
return -EFAULT;
The dev->private pointer is setup in the attach function to point to the
probed usb device. This value could be NULL if the attach fails. But,
since the comedi core is going to unload the driver anyway and does not
check for errors there is no gain by returning one.
After removing these checks from the comedi usb drivers the detach
functions required a bit of cleanup.
2. Remove all the printk noise in the detach functions
All of the printk output is really just noise. The user did a rmmod to
unload the driver, we really don't need to tell them about it.
Also, some of the messages are output using:
dev_dbg(dev->hw_dev, ...
or
dev_info(dev->hw_dev, ...
Unfortunately the hw_dev value is only used by drivers that are doing
DMA. For most drivers this variable is going to be NULL so the output
is not going to work as expected.
3. Refactor a couple static 'free_resource' functions into the detach
functions.
The 'free_resource' function is only being called by the detach and it
makes more sense to just absorb the code.
4. Remove a couple unnecessary braces for single statements.
5. Remove unnecessary comments.
Most of the comedi drivers appear to be based on the comedi skel driver
and have the comments from that driver included. These comments make
sense in the skel driver for reference but they don't need to be in any
of the actual drivers.
6. Remove all the extra whitespace.
It's not needed to make the functions any more readable.
7. Remove the now unused 'attached_successfully' variable in the
cb_pcimdda driver.
This variable was only used to conditionally output some driver noise
during the detach. Since all the printk's have been removed this
variable is no longer necessary.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It needs parentheses around the argument, so that it can be used with
complex arguments (e.g., "n+5").
Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Remove all the 'default N' lines in the comedi Kconfig. They should all
be 'default n' but that is the default anyway.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current error flow code was releasing the IB connection object and
calling iscsi_destroy_endpoint() directly without going through the
reference counting mechanism introduced in commit 39ff05d ("IB/iser:
Enhance disconnection logic for multi-pathing"). This resulted in a
double free of the iscsi endpoint object, which causes a kernel NULL
pointer dereference. Fix that by plugging into the IB conn reference
counting correctly.
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Enable IB ULPs to use a larger portion of the device EQs (which map to
IRQs). The mlx4_ib driver follows the mlx4_core framework of the EQs
to be divided among the device ports. In this scheme, for each IB
port, the number of allocated EQs follows the number of cores, subject
to other system constraints, such as number available MSI-X vectors.
Signed-off-by: Shlomo Pongratz <shlomop@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
When the thin pool target clears the discard_passdown parameter
internally, it incorrectly changes the table line reported to userspace.
This breaks dumb string comparisons on these table lines in generic
userspace device-mapper library code and leads to tables being reloaded
repeatedly when nothing is actually meant to be changing.
This patch corrects this by no longer changing the table line when
discard passdown was disabled.
We can still tell when discard passdown is overridden by looking for the
message "Discard unsupported by data device (sdX): Disabling discard passdown."
This automatic detection is also moved from the 'load' to the 'resume'
so that it is re-evaluated should the properties of underlying devices
change.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
There exist races in devio.c, below is one case,
and there are similar races in destroy_async()
and proc_unlinkurb(). Remove these races.
cancel_bulk_urbs() async_completed()
------------------- -----------------------
spin_unlock(&ps->lock);
list_move_tail(&as->asynclist,
&ps->async_completed);
wake_up(&ps->wait);
Lead to free_async() be triggered,
then urb and 'as' will be freed.
usb_unlink_urb(as->urb);
===> refer to the freed 'as'
Signed-off-by: Huajun Li <huajun.li.lee@gmail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Oncaphillis <oncaphillis@snafu.de>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The update_device callback is not needed and the function used here is
from the pci ehci driver. Without this patch we get a compile error if
ehci-platform is compiled without ehci-pci.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Cc: stable <stable@vger.kernel.org> [3.4]
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Hi Greg,
Here's the final Link Power Management patches, along with a couple of bug
fixes that have been sitting in my queue. I've fixed all the comments that
Alan and Andiry had on the Link PM patches, so I think they're ready to go.
Sarah Sharp
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.11 (GNU/Linux)
iQIcBAABAgAGBQJPttDmAAoJEBMGWMLi1Gc5IJgP/jPNhCjHWr+YqsmcvJdlHxkE
1TrMCScAhAk7OkAaZ+4xpFsD4G3bN5+SS4U6x3hEdhqgJIWbtDazOBctfVKezJQ1
uywnJNW08aW6GWYCTtoDVHY/ofLjpRnSRC21RXW4zKW8U4dHp1UcoCfkLRpqbb1C
/GYuLb03Ipl25+wDDDQAmFIs5IlEGHfE7a1r27I43MHIHvg6iw7rzgJPI5HKEIH2
3Usw4+DL1aMAlU1YKRwiwVoOVnmujzlb4a0ONhuBUdHKCGbfi6/Tce6lH0ElXavH
mJgv5S9Ro2H/rMtYFq1ZoR9NxeizqtKT2Dv0KOsWiFwZBOfhjvmDel62N+7w1akt
EWgahjASunwS56LBMg5ni0eK0VOt1kHQl3yeF6HmSdRftljN5Fke2r4BDA83sfl/
VggQPPoLNdHou9LRO+XLOKe3sW5+nIH/b+SJUvWYktCSN9wMPCH5wbXNp8WIh/7p
MvD2Kj7iqgF2PPzqpYGIwTHNwh5YdmnyYeCkr/IaoCBmUV0qD8HConsRN6USVIRI
aBCZR4APWlaTzhu/eP5inuuGwNBGTVi3aJKe/WgN2aG2TsYnAzKhmvbELpYaheZj
/Fe2itLuejVSjVsQI6KfhneCZyM45M7Ip8FTcEE1/z4R3cTEc5vE1adjFGWIzHRo
bHPQ0JRfpamuJkxaSTOY
=ixwg
-----END PGP SIGNATURE-----
Merge tag 'for-usb-next-2012-05-18' of git://git.kernel.org/pub/scm/linux/kernel/git/sarah/xhci into usb-next
xhci: Link PM and bug fixes for 3.5.
Hi Greg,
Here's the final Link Power Management patches, along with a couple of bug
fixes that have been sitting in my queue. I've fixed all the comments that
Alan and Andiry had on the Link PM patches, so I think they're ready to go.
Sarah Sharp
Without this patch, recovery will crash
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)
iQIVAwUAT7bVGznsnt1WYoG5AQL0ohAAvpF47NkSnuqw9gko25/Ndr5akrIC9kfz
YNzxsd0FvNSEQipGS4KgBcRxnFxbcVkmHL+pN8McmiDxNew1LW2+zdtV47RJngnQ
2slTUiSBLSHcvnOFblBrwIh+XpMdhv4FEMG13Si4tQaETtHp3JiNDr2JqvwbuKbo
aO/nW38DFNjEcB59X+9npknZYaymvavxso4J7iH/ec0Iys2c2h+jX5afewCXnbYr
Q6X2YlySUiUM3AXbgV0QI/w6xDM0TD+WWguHq411pgU1wHMYpHelYYwRGHSU73TJ
061K5WB83Q53A8czeRXK33x0xGr/AhQesTel+mlV3eODHoGSnsYxH8Zja7sV220h
HgTICrSvAFL2cvBz8dqJQ59KYH3yNo4Cie5xzmBxCuX6yyTxizgrQTp7L/HUy7RL
eL1SqNFTRJcwSl3MwmgbL57saBLw+/ejV+og7PNBCXSS9gZg39uJyn1uTqJZTrcL
PuBaizNG9HCYuR/pRTMsQGNWrksqk9r+hxwCJDIGb7xh9SBFI82YtQfK9F5fSB84
vdmIec8yUvwS/Gxhz+I+YB3kqk/nwfFRbVGfBWvJdRBOR0DsZphsBapsJ83LZqFb
VAa2nQL+NoHOweixv6RgiH4Y96SNHdWkvDJjj7R01BUDdpHeHMZuff07Effgqd64
Knk64XvWKQc=
=s7vy
-----END PGP SIGNATURE-----
Merge tag 'md-3.4-fixes' of git://neil.brown.name/md
Pull one more md bugfix from NeilBrown:
"Fix bug in recent fix to RAID10.
Without this patch, recovery will crash"
* tag 'md-3.4-fixes' of git://neil.brown.name/md:
md/raid10: fix transcription error in calc_sectors conversion.
Pull tile tree bugfix from Chris Metcalf:
"This fixes a security vulnerability (and correctness bug) in tilegx"
* 'stable' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tilegx: enable SYSCALL_WRAPPERS support
The old code was
sector_div(stride, fc);
the new code was
sector_dir(size, conf->near_copies);
'size' is right (the stride various wasn't really needed), but
'fc' means 'far_copies', and that is an important difference.
Signed-off-by: NeilBrown <neilb@suse.de>
Merge misc fixes from Andrew Morton.
* emailed from Andrew Morton <akpm@linux-foundation.org>: (4 patches)
frv: delete incorrect task prototypes causing compile fail
slub: missing test for partial pages flush work in flush_all()
fs, proc: fix ABBA deadlock in case of execution attempt of map_files/ entries
drivers/rtc/rtc-pl031.c: configure correct wday for 2000-01-01
Hub-initiated LPM is not good for USB communications devices. Comms
devices should be able to tell when their link can go into a lower power
state, because they know when an incoming transmission is finished.
Ideally, these devices would slam their links into a lower power state,
using the device-initiated LPM, after finishing the last packet of their
data transfer.
If we enable the idle timeouts for the parent hubs to enable
hub-initiated LPM, we will get a lot of useless LPM packets on the bus
as the devices reject LPM transitions when they're in the middle of
receiving data. Worse, some devices might blindly accept the
hub-initiated LPM and power down their radios while they're in the
middle of receiving a transmission.
The Intel Windows folks are disabling hub-initiated LPM for all USB
communications devices under a xHCI USB 3.0 host. In order to keep
the Linux behavior as close as possible to Windows, we need to do the
same in Linux.
Set the disable_hub_initiated_lpm flag for for all USB communications
drivers. I know there aren't currently any USB 3.0 devices that
implement these class specifications, but we should be ready if they do.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Hansjoerg Lipp <hjlipp@web.de>
Cc: Tilman Schmidt <tilman@imap.cc>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Jan Dumon <j.dumon@option.com>
Cc: Petko Manolov <petkan@users.sourceforge.net>
Cc: Steve Glendinning <steve.glendinning@smsc.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: Kalle Valo <kvalo@qca.qualcomm.com>
Cc: "Luis R. Rodriguez" <mcgrof@qca.qualcomm.com>
Cc: Jouni Malinen <jouni@qca.qualcomm.com>
Cc: Vasanthakumar Thiagarajan <vthiagar@qca.qualcomm.com>
Cc: Senthil Balasubramanian <senthilb@qca.qualcomm.com>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Brett Rudley <brudley@broadcom.com>
Cc: Roland Vossen <rvossen@broadcom.com>
Cc: Arend van Spriel <arend@broadcom.com>
Cc: "Franky (Zhenhui) Lin" <frankyl@broadcom.com>
Cc: Kan Yan <kanyan@broadcom.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
Cc: Ivo van Doorn <IvDoorn@gmail.com>
Cc: Gertjan van Wingerde <gwingerde@gmail.com>
Cc: Helmut Schaa <helmut.schaa@googlemail.com>
Cc: Herton Ronaldo Krzesinski <herton@canonical.com>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Chaoming Li <chaoming_li@realsil.com.cn>
Cc: Daniel Drake <dsd@gentoo.org>
Cc: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
All Intel xHCI host controllers support USB 3.0 Link Power Management.
The Panther Point xHCI host controller needs the xHCI driver to
calculate the U1 and U2 timeout values, because it will blindly accept a
MEL that would cause scheduling issues.
The Lynx Point xHCI host controller will reject MEL values that are too
high, but internally it implements the same algorithm that is needed for
Panther Point xHCI.
Simplify the code paths by just having the xHCI driver calculate what
the U1/U2 timeouts should be. Comments on the policy are in the code.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
The choice of U1 and U2 timeouts for USB 3.0 Link Power Management (LPM)
is highly host controller specific. Here are a few examples of why it's
host specific:
1. Setting the U1/U2 timeout too short may cause the link to go into
U1/U2 in between service intervals, which some hosts may tolerate,
and some may not.
2. The host controller has to modify its bus schedule in order to take
into account the Maximum Exit Latency (MEL) to bring all the links
from the host to the device into U0. If the MEL is too big, and it
takes too long to bring the links into an active state, the host
controller may not be able to service periodic endpoints in time.
3. Host controllers may also have scheduling limitations that force
them to disable U1 or U2 if a USB device is behind too many tiers of
hubs.
We could take an educated guess at what U1/U2 timeouts may work for a
particular host controller. However, that would result in a binary
search on every new configuration or alt setting installation, with
multiple failed Evaluate Context commands. Worse, the host may blindly
accept the timeouts and just fail to update its schedule for U1/U2 exit
latencies, which could result in randomly delayed periodic transfers.
Since we don't want to cause jitter in periodic transfers, or delay
config/alt setting changes too much, lay down a framework that xHCI
vendors can extend in order to add their own U1/U2 timeout policies.
To extend the framework, they will need to:
- Modify the PCI init code to add a new xhci->quirk for their host, and
set the XHCI_LPM_SUPPORT quirk flag.
- Add their own vendor-specific hooks, like the ones that will be added
in xhci_call_host_update_timeout_for_endpoint() and
xhci_check_tier_policy()
- Make the LPM enable/disable methods call those functions based on the
xhci->quirk for their host.
An example will be provided for the Intel xHCI host controller in the
next patch.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
