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  1. 14 6月, 2012 6 次提交
    • J
      USB: option: clean up probe coding style · 378fac2a
      由 Johan Hovold 提交于 
      Clean up option probe by introducing intermediate variables and fixing
up comments.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      378fac2a
    • J
      USB: option: use usb_{get,set}_serial_data · a276400d
      由 Johan Hovold 提交于 
      Use usb_{get,set}_serial_data to access usb-serial data.
Signed-off-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      a276400d
    • A
      USB: serial-generic: use a single set of device IDs · 0b84704a
      由 Alan Stern 提交于 
      The usb-serial-generic driver uses different device IDs for its USB
matching and its serial matching.  This can lead to problems: The
driver can end up getting bound to a USB interface without being
allowed to bind to the corresponding serial port.

This patch (as1557) fixes the problem by using the same device ID
table (the one that can be altered by the "vendor=" and "product="
module parameters) for both purposes.  The unused table is removed.
Now the driver will bind only to the intended devices.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
CC: Bjørn Mork <bjorn@mork.no>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0b84704a
    • B
      USB: serial: Enforce USB driver and USB serial driver match · 954c3f8a
      由 Bjørn Mork 提交于 
      We need to make sure that the USB serial driver we find
matches the USB driver whose probe we are currently
executing. Otherwise we will end up with USB serial
devices bound to the correct serial driver but wrong
USB driver.

An example of such cross-probing, where the usbserial_generic
USB driver has found the sierra serial driver:

May 29 18:26:15 nemi kernel: [ 4442.559246] usbserial_generic 4-4:1.0: Sierra USB modem converter detected
May 29 18:26:20 nemi kernel: [ 4447.556747] usbserial_generic 4-4:1.2: Sierra USB modem converter detected
May 29 18:26:25 nemi kernel: [ 4452.557288] usbserial_generic 4-4:1.3: Sierra USB modem converter detected

sysfs view of the same problem:

bjorn@nemi:~$ ls -l /sys/bus/usb/drivers/sierra/
total 0
--w------- 1 root root 4096 May 29 18:23 bind
lrwxrwxrwx 1 root root    0 May 29 18:23 module -> ../../../../module/usbserial
--w------- 1 root root 4096 May 29 18:23 uevent
--w------- 1 root root 4096 May 29 18:23 unbind
bjorn@nemi:~$ ls -l /sys/bus/usb-serial/drivers/sierra/
total 0
--w------- 1 root root 4096 May 29 18:23 bind
lrwxrwxrwx 1 root root    0 May 29 18:23 module -> ../../../../module/sierra
-rw-r--r-- 1 root root 4096 May 29 18:23 new_id
lrwxrwxrwx 1 root root    0 May 29 18:32 ttyUSB0 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.0/ttyUSB0
lrwxrwxrwx 1 root root    0 May 29 18:32 ttyUSB1 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.2/ttyUSB1
lrwxrwxrwx 1 root root    0 May 29 18:32 ttyUSB2 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.3/ttyUSB2
--w------- 1 root root 4096 May 29 18:23 uevent
--w------- 1 root root 4096 May 29 18:23 unbind

bjorn@nemi:~$ ls -l /sys/bus/usb/drivers/usbserial_generic/
total 0
lrwxrwxrwx 1 root root    0 May 29 18:33 4-4:1.0 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.0
lrwxrwxrwx 1 root root    0 May 29 18:33 4-4:1.2 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.2
lrwxrwxrwx 1 root root    0 May 29 18:33 4-4:1.3 -> ../../../../devices/pci0000:00/0000:00:1d.7/usb4/4-4/4-4:1.3
--w------- 1 root root 4096 May 29 18:33 bind
lrwxrwxrwx 1 root root    0 May 29 18:33 module -> ../../../../module/usbserial
--w------- 1 root root 4096 May 29 18:22 uevent
--w------- 1 root root 4096 May 29 18:33 unbind
bjorn@nemi:~$ ls -l /sys/bus/usb-serial/drivers/generic/
total 0
--w------- 1 root root 4096 May 29 18:33 bind
lrwxrwxrwx 1 root root    0 May 29 18:33 module -> ../../../../module/usbserial
-rw-r--r-- 1 root root 4096 May 29 18:33 new_id
--w------- 1 root root 4096 May 29 18:22 uevent
--w------- 1 root root 4096 May 29 18:33 unbind

So we end up with a mismatch between the USB driver and the
USB serial driver.  The reason for the above is simple: The
USB driver probe will succeed if *any* registered serial
driver matches, and will use that serial driver for all
serial driver functions.

This makes ref counting go wrong. We count the USB driver
as used, but not the USB serial driver.  This may result
in Oops'es as demonstrated by Johan Hovold <jhovold@gmail.com>:

[11811.646396] drivers/usb/serial/usb-serial.c: get_free_serial 1
[11811.646443] drivers/usb/serial/usb-serial.c: get_free_serial - minor base = 0
[11811.646460] drivers/usb/serial/usb-serial.c: usb_serial_probe - registering ttyUSB0
[11811.646766] usb 6-1: pl2303 converter now attached to ttyUSB0
[11812.264197] USB Serial deregistering driver FTDI USB Serial Device
[11812.264865] usbcore: deregistering interface driver ftdi_sio
[11812.282180] USB Serial deregistering driver pl2303
[11812.283141] pl2303 ttyUSB0: pl2303 converter now disconnected from ttyUSB0
[11812.283272] usbcore: deregistering interface driver pl2303
[11812.301056] USB Serial deregistering driver generic
[11812.301186] usbcore: deregistering interface driver usbserial_generic
[11812.301259] drivers/usb/serial/usb-serial.c: usb_serial_disconnect
[11812.301823] BUG: unable to handle kernel paging request at f8e7438c
[11812.301845] IP: [<f8e38445>] usb_serial_disconnect+0xb5/0x100 [usbserial]
[11812.301871] *pde = 357ef067 *pte = 00000000
[11812.301957] Oops: 0000 [#1] PREEMPT SMP
[11812.301983] Modules linked in: usbserial(-) [last unloaded: pl2303]
[11812.302008]
[11812.302019] Pid: 1323, comm: modprobe Tainted: G        W    3.4.0-rc7+ #101 Dell Inc. Vostro 1520/0T816J
[11812.302115] EIP: 0060:[<f8e38445>] EFLAGS: 00010246 CPU: 1
[11812.302130] EIP is at usb_serial_disconnect+0xb5/0x100 [usbserial]
[11812.302141] EAX: f508a180 EBX: f508a180 ECX: 00000000 EDX: f8e74300
[11812.302151] ESI: f5050800 EDI: 00000001 EBP: f5141e78 ESP: f5141e58
[11812.302160]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[11812.302170] CR0: 8005003b CR2: f8e7438c CR3: 34848000 CR4: 000007d0
[11812.302180] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[11812.302189] DR6: ffff0ff0 DR7: 00000400
[11812.302199] Process modprobe (pid: 1323, ti=f5140000 task=f61e2bc0 task.ti=f5140000)
[11812.302209] Stack:
[11812.302216]  f8e3be0f f8e3b29c f8e3ae00 00000000 f513641c f5136400 f513641c f507a540
[11812.302325]  f5141e98 c133d2c1 00000000 00000000 f509c400 f513641c f507a590 f5136450
[11812.302372]  f5141ea8 c12f0344 f513641c f507a590 f5141ebc c12f0c67 00000000 f507a590
[11812.302419] Call Trace:
[11812.302439]  [<c133d2c1>] usb_unbind_interface+0x51/0x190
[11812.302456]  [<c12f0344>] __device_release_driver+0x64/0xb0
[11812.302469]  [<c12f0c67>] driver_detach+0x97/0xa0
[11812.302483]  [<c12f001c>] bus_remove_driver+0x6c/0xe0
[11812.302500]  [<c145938d>] ? __mutex_unlock_slowpath+0xcd/0x140
[11812.302514]  [<c12f0ff9>] driver_unregister+0x49/0x80
[11812.302528]  [<c1457df6>] ? printk+0x1d/0x1f
[11812.302540]  [<c133c50d>] usb_deregister+0x5d/0xb0
[11812.302557]  [<f8e37c55>] ? usb_serial_deregister+0x45/0x50 [usbserial]
[11812.302575]  [<f8e37c8d>] usb_serial_deregister_drivers+0x2d/0x40 [usbserial]
[11812.302593]  [<f8e3a6e2>] usb_serial_generic_deregister+0x12/0x20 [usbserial]
[11812.302611]  [<f8e3acf0>] usb_serial_exit+0x8/0x32 [usbserial]
[11812.302716]  [<c1080b48>] sys_delete_module+0x158/0x260
[11812.302730]  [<c110594e>] ? mntput+0x1e/0x30
[11812.302746]  [<c145c3c3>] ? sysenter_exit+0xf/0x18
[11812.302746]  [<c107777c>] ? trace_hardirqs_on_caller+0xec/0x170
[11812.302746]  [<c145c390>] sysenter_do_call+0x12/0x36
[11812.302746] Code: 24 02 00 00 e8 dd f3 20 c8 f6 86 74 02 00 00 02 74 b4 8d 86 4c 02 00 00 47 e8 78 55 4b c8 0f b6 43 0e 39 f8 7f a9 8b 53 04 89 d8 <ff> 92 8c 00 00 00 89 d8 e8 0e ff ff ff 8b 45 f0 c7 44 24 04 2f
[11812.302746] EIP: [<f8e38445>] usb_serial_disconnect+0xb5/0x100 [usbserial] SS:ESP 0068:f5141e58
[11812.302746] CR2: 00000000f8e7438c

Fix by only evaluating serial drivers pointing back to the
USB driver we are currently probing.  This still allows two
or more drivers to match the same device, running their
serial driver probes to sort out which one to use.

Cc: stable@vger.kernel.org # 3.0, 3.2, 3.3, 3.4
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Reviewed-by: NFelipe Balbi <balbi@ti.com>
Tested-by: NJohan Hovold <jhovold@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      954c3f8a
    • A
      USB: add NO_D3_DURING_SLEEP flag and revert 151b6128 · c2fb8a3f
      由 Alan Stern 提交于 
      This patch (as1558) fixes a problem affecting several ASUS computers:
The machine crashes or corrupts memory when going into suspend if the
ehci-hcd driver is bound to any controllers.  Users have been forced
to unbind or unload ehci-hcd before putting their systems to sleep.

After extensive testing, it was determined that the machines don't
like going into suspend when any EHCI controllers are in the PCI D3
power state.  Presumably this is a firmware bug, but there's nothing
we can do about it except to avoid putting the controllers in D3
during system sleep.

The patch adds a new flag to indicate whether the problem is present,
and avoids changing the controller's power state if the flag is set.
Runtime suspend is unaffected; this matters only for system suspend.
However as a side effect, the controller will not respond to remote
wakeup requests while the system is asleep.  Hence USB wakeup is not
functional -- but of course, this is already true in the current state
of affairs.

A similar patch has already been applied as commit
151b6128 (USB: EHCI: fix crash during
suspend on ASUS computers).  The patch supersedes that one and reverts
it.  There are two differences:

	The old patch added the flag at the USB level; this patch
	adds it at the PCI level.

	The old patch applied to all chipsets with the same vendor,
	subsystem vendor, and product IDs; this patch makes an
	exception for a known-good system (based on DMI information).
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Tested-by: NDâniel Fraga <fragabr@gmail.com>
Tested-by: NAndrey Rahmatullin <wrar@wrar.name>
Tested-by: NSteven Rostedt <rostedt@goodmis.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c2fb8a3f
    • R
      USB: move transceiver from ehci_hcd and ohci_hcd to hcd and rename it as phy · c2e935a7
      由 Richard Zhao 提交于 
       - to decrease redundant since both ehci_hcd and ohci_hcd have the same variable
 - it helps access phy in usb core code
 - phy is more meaningful than transceiver
Signed-off-by: NRichard Zhao <richard.zhao@freescale.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c2e935a7
  3. 13 6月, 2012 12 次提交
  5. 04 6月, 2012 12 次提交
  7. 22 5月, 2012 3 次提交
    • S
      xhci: Fix DIV_ROUND_UP compile error. · c88db160
      由 Sarah Sharp 提交于 
      Fengguang reports that the xHCI driver isn't linked properly on his
machine:

ERROR: "__udivdi3" [drivers/usb/host/xhci-hcd.ko] undefined!
ERROR: "handle_edge_irq" [drivers/gpio/gpio-pch.ko] undefined!
ERROR: "irq_to_desc" [drivers/gpio/gpio-pch.ko] undefined!

The driver compiles fine on my 64-bit box (gcc version 4.6.1).
Fengguang thinks it's because the xHCI driver was using DIV_ROUND_UP()
instead of DIV_ROUND_UP_ULL() with arguments that were unsigned long
long variables.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NWu Fengguang <wfg@linux.intel.com>
      c88db160
    • S
      xhci: Fix compile with CONFIG_USB_SUSPEND=n · b01bcbf7
      由 Sarah Sharp 提交于 
      The USB 2.0 Link PM code is conditionally compiled when
CONFIG_USB_SUSPEND=y.  I believe that's a mistake, since Link PM is not
directly related to USB device suspend and Link PM is implemented
without relying on any of the suspend code in the USB core.  For now,
keep the USB 2.0 Link PM code conditionally compiled if
CONFIG_USB_SUSPEND=y.

This patch does move the code to implement USB 3.0 Link PM out of the
xHCI driver #ifdefs for CONFIG_USB_SUSPEND and moves it into a section
dependent on CONFIG_PM.  The USB core functions for USB 3.0 Link PM are
already conditionally compiled when CONFIG_PM=y.
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      b01bcbf7
    • S
      USB: Fix core compile with CONFIG_USB_SUSPEND=n · e9261fb6
      由 Sarah Sharp 提交于 
      When CONFIG_PM=n, make sure that the usb_[unlocked_][en/dis]able_lpm
declarations are visible in include/linux/usb.h, and exported from
drivers/usb/core/hub.c.

Before this patch, if CONFIG_USB_SUSPEND was turned off, it would cause
build errors:

drivers/usb/core/hub.c: In function 'usb_disable_lpm':
drivers/usb/core/hub.c:3394:2: error: implicit declaration of function 'usb_enable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/hub.c: At top level:
drivers/usb/core/hub.c:3424:6: warning: conflicting types for 'usb_enable_lpm' [enabled by default]
drivers/usb/core/hub.c:3394:2: note: previous implicit declaration of 'usb_enable_lpm' was here
drivers/usb/core/driver.c: In function 'usb_probe_interface':
drivers/usb/core/driver.c:339:2: error: implicit declaration of function 'usb_unlocked_disable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/driver.c:364:3: error: implicit declaration of function 'usb_unlocked_enable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/message.c: In function 'usb_set_interface':
drivers/usb/core/message.c:1314:2: error: implicit declaration of function 'usb_disable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/message.c:1323:3: error: implicit declaration of function 'usb_enable_lpm' [-Werror=implicit-function-declaration]
drivers/usb/core/message.c:1368:2: error: implicit declaration of function 'usb_unlocked_enable_lpm' [-Werror=implicit-function-declaration]
Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Reported-by: NChen Peter-B29397 <B29397@freescale.com>
      e9261fb6
  9. 21 5月, 2012 1 次提交
  11. 20 5月, 2012 1 次提交
    • M
      USB: EHCI: fix command register configuration lost problem · 1c01f1d9
      由 Ming Lei 提交于 
      The 3d9545cc(EHCI: maintain the
ehci->command value properly) introducs one command register
configuration lost problem by the below line in ehci_reset:

	ehci->command = ehci_readl(ehci, &ehci->regs->command);

After writting RESET into command register, it is restored to
its default value per EHCI spec[1], so the previous configuration
will be lost, and may introduce some problems reported recently:
	- imx51 Babbage board detect usb hub failed[2], reported
	by Richard Zhao.
	- mouse and keyboard hangs in linux-next found by
	Dan Carpenter and Greg-KH.

So this patch just removes the line to fix these problems, and
keep configurating command register consistent as before the commit
3d9545cc(EHCI: maintain the ehci->command value properly).

[1], 4.1 Host Controller Initialization of EHCI Specification 1.0
[2], failed dmesg log:
	usb 1-1: new high-speed USB device number 2 using mxc-ehci
	hub 1-1:1.0: USB hub found
	hub 1-1:1.0: 7 ports detected
	mxc-ehci mxc-ehci.1: fatal error
	mxc-ehci mxc-ehci.1: HC died; cleaning up
	mxc-ehci mxc-ehci.1: force halt; handshake f5780344 00004000 00004000 -> -110
	mxc-ehci mxc-ehci.1: HC died; cleaning up
	usb 1-1: USB disconnect, device number 2
Reported-by: NRichard Zhao <richard.zhao@freescale.com>
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Reported-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Chen Peter-B29397 <B29397@freescale.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NMing Lei <ming.lei@canonical.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1c01f1d9
  13. 19 5月, 2012 5 次提交
    • H
      USB: Remove races in devio.c · 4e09dcf2
      由 Huajun Li 提交于 
      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: NHuajun 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: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4e09dcf2
    • H
      USB: ehci-platform: remove update_device · 8377c94f
      由 Hauke Mehrtens 提交于 
      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: NHauke Mehrtens <hauke@hauke-m.de>
Cc: stable <stable@vger.kernel.org> [3.4]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8377c94f
    • S
      USB: Disable hub-initiated LPM for comms devices. · e1f12eb6
      由 Sarah Sharp 提交于 
      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: NSarah 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: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      e1f12eb6
    • S
      xhci: Add Intel U1/U2 timeout policy. · e3567d2c
      由 Sarah Sharp 提交于 
      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: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      e3567d2c
    • S
      xhci: Add infrastructure for host-specific LPM policies. · 3b3db026
      由 Sarah Sharp 提交于 
      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: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      3b3db026