1. 19 5月, 2012 5 次提交
    • S
      USB: Add macros for interrupt endpoint types. · 6538eafc
      Sarah Sharp 提交于
      The USB 3.0 spec defines a new way of differentiating interrupt
      endpoints.  The idea is that some interrupt endpoints are used for
      notifications, i.e. they continually NAK the transfer until something
      changes on the device.  Other interrupt endpoints are used as a way to
      periodically transfer data.
      
      The USB 3.0 endpoint descriptor uses bits 5:4 of bmAttributes for
      interrupt endpoints, to define the endpoint as either a Notification
      endpoint, or a Periodic endpoint.  Introduce macros to dig out that
      information.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      6538eafc
    • S
      USB: Disable USB 3.0 LPM in critical sections. · 8306095f
      Sarah Sharp 提交于
      There are several places where the USB core needs to disable USB 3.0
      Link PM:
       - usb_bind_interface
       - usb_unbind_interface
       - usb_driver_claim_interface
       - usb_port_suspend/usb_port_resume
       - usb_reset_and_verify_device
       - usb_set_interface
       - usb_reset_configuration
       - usb_set_configuration
      
      Use the new LPM disable/enable functions to temporarily disable LPM
      around these critical sections.
      
      We need to protect the critical section around binding and unbinding USB
      interface drivers.  USB drivers may want to disable hub-initiated USB
      3.0 LPM, which will change the value of the U1/U2 timeouts that the xHCI
      driver will install.  We need to disable LPM completely until the driver
      is bound to the interface, and the driver has a chance to enable
      whatever alternate interface setting it needs in its probe routine.
      Then re-enable USB3 LPM, and recalculate the U1/U2 timeout values.
      
      We also need to disable LPM in usb_driver_claim_interface,
      because drivers like usbfs can bind to an interface through that
      function.  Note, there is no way currently for userspace drivers to
      disable hub-initiated USB 3.0 LPM.  Revisit this later.
      
      When a driver is unbound, the U1/U2 timeouts may change because we are
      unbinding the last driver that needed hub-initiated USB 3.0 LPM to be
      disabled.
      
      USB LPM must be disabled when a USB device is going to be suspended.
      The USB 3.0 spec does not define a state transition from U1 or U2 into
      U3, so we need to bring the device into U0 by disabling LPM before we
      can place it into U3.  Therefore, call usb_unlocked_disable_lpm() in
      usb_port_suspend(), and call usb_unlocked_enable_lpm() in
      usb_port_resume().  If the port suspend fails, make sure to re-enable
      LPM by calling usb_unlocked_enable_lpm(), since usb_port_resume() will
      not be called on a failed port suspend.
      
      USB 3.0 devices lose their USB 3.0 LPM settings (including whether USB
      device-initiated LPM is enabled) across device suspend.  Therefore,
      disable LPM before the device will be reset in
      usb_reset_and_verify_device(), and re-enable LPM after the reset is
      complete and the configuration/alt settings are re-installed.
      
      The calculated U1/U2 timeout values are heavily dependent on what USB
      device endpoints are currently enabled.  When any of the enabled
      endpoints on the device might change, due to a new configuration, or new
      alternate interface setting, we need to first disable USB 3.0 LPM, add
      or delete endpoints from the xHCI schedule, install the new interfaces
      and alt settings, and then re-enable LPM.  Do this in usb_set_interface,
      usb_reset_configuration, and usb_set_configuration.
      
      Basically, there is a call to disable and then enable LPM in all
      functions that lock the bandwidth_mutex.  One exception is
      usb_disable_device, because the device is disconnecting or otherwise
      going away, and we should not care about whether USB 3.0 LPM is enabled.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      8306095f
    • S
      USB: Add support to enable/disable USB3 link states. · 1ea7e0e8
      Sarah Sharp 提交于
      There are various functions within the USB core that will need to
      disable USB 3.0 link power states.  For example, when a USB device
      driver is being bound to an interface, we need to disable USB 3.0 LPM
      until we know if the driver will allow hub-initiated LPM transitions.
      Another example is when the USB core is switching alternate interface
      settings.  The USB 3.0 timeout values are dependent on what endpoints
      are enabled, so we want to ensure that LPM is disabled until the new alt
      setting is fully installed.
      
      Multiple functions need to disable LPM, and those functions can even be
      nested.  For example, usb_bind_interface() could disable LPM, and then
      call into the driver probe function, which may attempt to switch to a
      different alt setting.  Therefore, we need to keep a count of the number
      of functions that require LPM to be disabled at any point in time.
      
      Introduce two new USB core API calls, usb_disable_lpm() and
      usb_enable_lpm().  These functions increment and decrement a new
      variable in the usb_device, lpm_disable_count.  If usb_disable_lpm()
      fails, it will call usb_enable_lpm() in order to balance the
      lpm_disable_count.
      
      These two new functions must be called with the bandwidth_mutex locked.
      If the bandwidth_mutex is not already held by the caller, it should
      instead call usb_unlocked_disable_lpm() and usb_enable_lpm(), which take
      the bandwidth_mutex before calling usb_disable_lpm() and
      usb_enable_lpm(), respectively.
      
      Introduce a new variable (timeout) in the usb3_lpm_params structure to
      keep track of the currently enabled U1/U2 timeout values.  When
      usb_disable_lpm() is called, and the USB device has the U1 or U2
      timeouts set to a non-zero value (meaning either device-initiated or
      hub-initiated LPM is enabled), attempt to disable LPM, regardless of the
      state of the lpm_disable_count.  We want to ensure that all callers can
      be guaranteed that LPM is disabled if usb_disable_lpm() returns zero.
      
      Otherwise the following scenario could occur:
      
      1. Driver A is being bound to interface 1.  usb_probe_interface()
      disables LPM.  Driver A doesn't care if hub-initiated LPM is enabled, so
      even though usb_disable_lpm() fails, the probe of the driver continues,
      and the bandwidth mutex is dropped.
      
      2. Meanwhile, Driver B is being bound to interface 2.
      usb_probe_interface() grabs the bandwidth mutex and calls
      usb_disable_lpm().  That call should attempt to disable LPM, even
      though the lpm_disable_count is set to 1 by Driver A.
      
      For usb_enable_lpm(), we attempt to enable LPM only when the
      lpm_disable_count is zero.  If some step in enabling LPM fails, it will
      only have a minimal impact on power consumption, and all USB device
      drivers should still work properly.  Therefore don't bother to return
      any error codes.
      
      Don't enable device-initiated LPM if the device is unconfigured.  The
      USB device will only accept the U1/U2_ENABLE control transfers in the
      configured state.  Do enable hub-initiated LPM in that case, since
      devices are allowed to accept the LGO_Ux link commands in any state.
      
      Don't enable or disable LPM if the device is marked as not being LPM
      capable.  This can happen if:
       - the USB device doesn't have a SS BOS descriptor,
       - the device's parent hub has a zeroed bHeaderDecodeLatency value, or
       - the xHCI host doesn't support LPM.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Cc: Andiry Xu <andiry.xu@amd.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      1ea7e0e8
    • S
      USB: Allow drivers to disable hub-initiated LPM. · 8afa408c
      Sarah Sharp 提交于
      USB 3.0 Link Power Management (LPM) is designed to allow individual
      links in the bus to go into lower power states.  There are two ways a
      link can enter a lower power state:
      
      1. Device-initiated LPM.  When a USB device decides it can go into a
      lower power link state, it sends a message to the parent hub, telling it
      to go into either U1 or U2.  Device-initiated LPM is good for devices
      that send data to the host, like communications devices.
      
      2. Hub-initiated LPM.  After the link has been idle for a specific
      amount of time, the parent hub will request that the child go into a
      lower power state.  The child can refuse that request.  For example, a
      USB modem may want to refuse the LPM request if it is in the middle of
      receiving a text message.  Hub-initiated LPM is good for devices where
      only the host initiates the data transfer, like USB printers or USB mass
      storage devices.
      
      Links will be automatically placed into higher power states by the USB
      hubs and roothubs whenever the host starts a USB transmission.
      
      Introduce a new usb_driver flag, disable_hub_initiated_lpm, that allows
      drivers to disable hub-initiated LPM.
      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: Oliver Neukum <oliver@neukum.name>
      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>
      Cc: linux-bluetooth@vger.kernel.org
      Cc: gigaset307x-common@lists.sourceforge.net
      Cc: netdev@vger.kernel.org
      Cc: linux-usb@vger.kernel.org
      Cc: linux-wireless@vger.kernel.org
      Cc: ath9k-devel@lists.ath9k.org
      Cc: libertas-dev@lists.infradead.org
      Cc: users@rt2x00.serialmonkey.com
      8afa408c
    • S
      USB: Calculate USB 3.0 exit latencies for LPM. · 51e0a012
      Sarah Sharp 提交于
      There are several different exit latencies associated with coming out of
      the U1 or U2 lower power link state.
      
      Device Exit Latency (DEL) is the maximum time it takes for the USB
      device to bring its upstream link into U0.  That can be found in the
      SuperSpeed Extended Capabilities BOS descriptor for the device.  The
      time it takes for a particular link in the tree to exit to U0 is the
      maximum of either the parent hub's U1/U2 DEL, or the child's U1/U2 DEL.
      
      Hubs introduce a further delay that effects how long it takes a child
      device to transition to U0.  When a USB 3.0 hub receives a header
      packet, it takes some time to decode that header and figure out which
      downstream port the packet was destined for.  If the port is not in U0,
      this hub header decode latency will cause an additional delay for
      bringing the child device to U0.  This Hub Header Decode Latency is
      found in the USB 3.0 hub descriptor.
      
      We can use DEL and the header decode latency, along with additional
      latencies imposed by each additional hub tier, to figure out the exit
      latencies for both host-initiated and device-initiated exit to U0.
      
      The Max Exit Latency (MEL) is the worst-case time it will take for a
      host-initiated exit to U0, based on whether U1 or U2 link states are
      enabled.  The ping or packet must traverse the path to the device, and
      each hub along the way incurs the hub header decode latency in order to
      figure out which device the transfer was bound for.  We say worst-case,
      because some hubs may not be in the lowest link state that is enabled.
      See the examples in section C.2.2.1.
      
      Note that "HSD" is a "host specific delay" that the power appendix
      architect has not been able to tell me how to calculate.  There's no way
      to get HSD from the xHCI registers either, so I'm simply ignoring it.
      
      The Path Exit Latency (PEL) is the worst-case time it will take for a
      device-initiate exit to U0 to place all the links from the device to the
      host into U0.
      
      The System Exit Latency (SEL) is another device-initiated exit latency.
      SEL is useful for USB 3.0 devices that need to send data to the host at
      specific intervals.  The device may send an NRDY to indicate it isn't
      ready to send data, then put its link into a lower power state.  If it
      needs to have that data transmitted at a specific time, it can use SEL
      to back calculate when it will need to bring the link back into U0 to
      meet its deadlines.
      
      SEL is the worst-case time from the device-initiated exit to U0, to when
      the device will receive a packet from the host controller.  It includes
      PEL, the time it takes for an ERDY to get to the host, a host-specific
      delay for the host to process that ERDY, and the time it takes for the
      packet to traverse the path to the device.  See Figure C-2 in the USB
      3.0 bus specification.
      
      Note: I have not been able to get good answers about what the
      host-specific delay to process the ERDY should be.  The Intel HW
      developers say it will be specific to the platform the xHCI host is
      integrated into, and they say it's negligible.  Ignore this too.
      
      Separate from these four exit latencies are the U1/U2 timeout values we
      program into the parent hubs.  These timeouts tell the hub to attempt to
      place the device into a lower power link state after the link has been
      idle for that amount of time.
      
      Create two arrays (one for U1 and one for U2) to store mel, pel, sel,
      and the timeout values.  Store the exit latency values in nanosecond
      units, since that's the smallest units used (DEL is in us, but the Hub
      Header Decode Latency is in ns).
      
      If a USB 3.0 device doesn't have a SuperSpeed Extended Capabilities BOS
      descriptor, it's highly unlikely it will be able to handle LPM requests
      properly.  So it's best to disable LPM for devices that don't have this
      descriptor, and any children beneath it, if it's a USB 3.0 hub.  Warn
      users when that happens, since it means they have a non-compliant USB
      3.0 device or hub.
      
      This patch assumes a simplified design where links deep in the tree will
      not have U1 or U2 enabled unless all their parent links have the
      corresponding LPM state enabled.  Eventually, we might want to allow a
      different policy, and we can revisit this patch when that happens.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      51e0a012
  2. 18 5月, 2012 1 次提交
  3. 16 5月, 2012 1 次提交
  4. 15 5月, 2012 3 次提交
  5. 12 5月, 2012 4 次提交
  6. 11 5月, 2012 3 次提交
  7. 09 5月, 2012 1 次提交
    • G
      USB: serial: rework usb_serial_register/deregister_drivers() · 68e24113
      Greg Kroah-Hartman 提交于
      This reworks the usb_serial_register_drivers() and
      usb_serial_deregister_drivers() to not need a pointer to a struct
      usb_driver anymore.  The usb_driver structure is now created dynamically
      and registered and unregistered as needed.
      
      This saves lines of code in each usb-serial driver.  All in-kernel users
      of these functions were also fixed up at this time.  The pl2303 driver
      was tested that everything worked properly.
      
      Thanks for the idea to do this from Alan Stern.
      
      Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Al Borchers <alborchers@steinerpoint.com>
      Cc: Aleksey Babahin <tamerlan311@gmail.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Andrew Worsley <amworsley@gmail.com>
      Cc: Bart Hartgers <bart.hartgers@gmail.com>
      Cc: Bill Pemberton <wfp5p@virginia.edu>
      Cc: Dan Carpenter <error27@gmail.com>
      Cc: Dan Williams <dcbw@redhat.com>
      Cc: Donald Lee <donald@asix.com.tw>
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Gary Brubaker <xavyer@ix.netcom.com>
      Cc: Jesper Juhl <jj@chaosbits.net>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Johan Hovold <jhovold@gmail.com>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Kautuk Consul <consul.kautuk@gmail.com>
      Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
      Cc: Lonnie Mendez <dignome@gmail.com>
      Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com>
      Cc: Matthias Urlichs <smurf@smurf.noris.de>
      Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
      Cc: Michal Sroczynski <msroczyn@gmail.com>
      Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl>
      Cc: Oliver Neukum <oliver@neukum.name>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Peter Berger <pberger@brimson.com>
      Cc: Preston Fick <preston.fick@silabs.com>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Rigbert Hamisch <rigbert@gmx.de>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Simon Arlott <simon@fire.lp0.eu>
      Cc: Support Department <support@connecttech.com>
      Cc: Thomas Tuttle <ttuttle@chromium.org>
      Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
      Cc: Wang YanQing <Udknight@gmail.com>
      Cc: William Greathouse <wgreathouse@smva.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      68e24113
  8. 08 5月, 2012 3 次提交
    • J
      net: compare_ether_addr[_64bits]() has no ordering · 1c430a72
      Johannes Berg 提交于
      Neither compare_ether_addr() nor compare_ether_addr_64bits()
      (as it can fall back to the former) have comparison semantics
      like memcmp() where the sign of the return value indicates sort
      order. We had a bug in the wireless code due to a blind memcmp
      replacement because of this.
      
      A cursory look suggests that the wireless bug was the only one
      due to this semantic difference.
      Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1c430a72
    • G
      USB: serial: remove bizarre generic_serial probe function · 2edd284b
      Greg Kroah-Hartman 提交于
      I can't remember why I wrote it like this many many years ago, but it's
      not needed at all, let's rely on the usb-serial core for this function,
      especially as it is being overridden by it anyway.
      
      This lets us make usb_serial_probe() a static function, which it should
      be.
      
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2edd284b
    • G
      USB: serial: remove usb_serial_disconnect call in all drivers · 32078f91
      Greg Kroah-Hartman 提交于
      This is now set by the usb-serial core, no need for the driver to
      individually set it.
      
      Thanks to Alan Stern for the idea to get rid of it.
      
      Cc: William Greathouse <wgreathouse@smva.com>
      Cc: Matthias Bruestle and Harald Welte <support@reiner-sct.com>
      Cc: Lonnie Mendez <dignome@gmail.com>
      Cc: Peter Berger <pberger@brimson.com>
      Cc: Al Borchers <alborchers@steinerpoint.com>
      Cc: Gary Brubaker <xavyer@ix.netcom.com>
      Cc: Oliver Neukum <oliver@neukum.name>
      Cc: Matthias Urlichs <smurf@smurf.noris.de>
      Cc: Support Department <support@connecttech.com>
      Cc: Rusty Russell <rusty@rustcorp.com.au>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
      Cc: Kautuk Consul <consul.kautuk@gmail.com>
      Cc: Bill Pemberton <wfp5p@virginia.edu>
      Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
      Cc: Bart Hartgers <bart.hartgers@gmail.com>
      Cc: Johan Hovold <jhovold@gmail.com>
      Cc: Preston Fick <preston.fick@silabs.com>
      Cc: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
      Cc: Simon Arlott <simon@fire.lp0.eu>
      Cc: Andrew Worsley <amworsley@gmail.com>
      Cc: "Michał Wróbel" <michal.wrobel@flytronic.pl>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Cc: "Eric W. Biederman" <ebiederm@xmission.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Aleksey Babahin <tamerlan311@gmail.com>
      Cc: Dan Carpenter <error27@gmail.com>
      Cc: Jiri Kosina <jkosina@suse.cz>
      Cc: Donald Lee <donald@asix.com.tw>
      Cc: Julia Lawall <julia@diku.dk>
      Cc: Michal Sroczynski <msroczyn@gmail.com>
      Cc: Wang YanQing <Udknight@gmail.com>
      Cc: Dan Williams <dcbw@redhat.com>
      Cc: Thomas Tuttle <ttuttle@chromium.org>
      Cc: Rigbert Hamisch <rigbert@gmx.de>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
      Cc: Jesper Juhl <jj@chaosbits.net>
      Cc: Adhir Ramjiawan <adhirramjiawan0@gmail.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      32078f91
  9. 05 5月, 2012 2 次提交
    • L
      seqlock: add 'raw_seqcount_begin()' function · 4f988f15
      Linus Torvalds 提交于
      The normal read_seqcount_begin() function will wait for any current
      writers to exit their critical region by looping until the sequence
      count is even.
      
      That "wait for sequence count to stabilize" is the right thing to do if
      the read-locker will just retry the whole operation on contention: no
      point in doing a potentially expensive reader sequence if we know at the
      beginning that we'll just end up re-doing it all.
      
      HOWEVER.  Some users don't actually retry the operation, but instead
      will abort and do the operation with proper locking.  So the sequence
      count case may be the optimistic quick case, but in the presense of
      writers you may want to do full locking in order to guarantee forward
      progress.  The prime example of this would be the RCU name lookup.
      
      And in that case, you may well be better off without the "retry early",
      and are in a rush to instead get to the failure handling.  Thus this
      "raw" interface that just returns the sequence number without testing it
      - it just forces the low bit to zero so that read_seqcount_retry() will
      always fail such a "active concurrent writer" scenario.
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4f988f15
    • L
      Fix __read_seqcount_begin() to use ACCESS_ONCE for sequence value read · 2f624278
      Linus Torvalds 提交于
      We really need to use a ACCESS_ONCE() on the sequence value read in
      __read_seqcount_begin(), because otherwise the compiler might end up
      reloading the value in between the test and the return of it.  As a
      result, it might end up returning an odd value (which means that a write
      is in progress).
      
      If the reader is then fast enough that that odd value is still the
      current one when the read_seqcount_retry() is done, we might end up with
      a "successful" read sequence, even despite the concurrent write being
      active.
      
      In practice this probably never really happens - there just isn't
      anything else going on around the read of the sequence count, and the
      common case is that we end up having a read barrier immediately
      afterwards.
      
      So the code sequence in which gcc might decide to reaload from memory is
      small, and there's no reason to believe it would ever actually do the
      reload.  But if the compiler ever were to decide to do so, it would be
      incredibly annoying to debug.  Let's just make sure.
      
      Cc: stable@kernel.org
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2f624278
  10. 04 5月, 2012 1 次提交
  11. 02 5月, 2012 2 次提交
    • R
      USB: Add driver for NXP ISP1301 USB transceiver · 8b7c3b68
      Roland Stigge 提交于
      This new driver registers the NXP ISP1301 chip via the I2C subsystem.  The chip
      is the USB transceiver shared by ohci-nxp, lpc32xx_udc (gadget) and
      isp1301_omap.
      
      ISP1301 is a very low-level driver that primarily separates out the I2C client
      registration of the ISP1301 chip (including instantiation via DT), used by
      other drivers, and declares the chip's registers. It's only a helper driver for
      some OHCI and USB device drivers.  The driver can be considered as a register
      set extension of ohci-nxp, lpc32xx-udc and isp1301_omap, which in turn know
      best what to do with the low level functionality (individual ISP1301 registers
      and timing, see the different initialization strategies in those drivers).
      Those drivers previously internally duplicated ISP1301 register definitions
      which is solved by this new isp1301 driver. The ISP1301 registers exposed via
      isp1301.h can be accessed by other drivers using it with standard i2c_smbus_*()
      accesses.
      
      Following patches let the respective USB host and gadget drivers use this
      driver, instead of duplicating ISP1301 handling.
      Signed-off-by: NRoland Stigge <stigge@antcom.de>
      Acked-by: NArnd Bergmann <arnd@arndb.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8b7c3b68
    • O
      usbhid: prevent deadlock during timeout · 8815bb09
      Oliver Neukum 提交于
      On some HCDs usb_unlink_urb() can directly call the
      completion handler. That limits the spinlocks that can
      be taken in the handler to locks not held while calling
      usb_unlink_urb()
      To prevent a race with resubmission, this patch exposes
      usbcore's infrastructure for blocking submission, uses it
      and so drops the lock without causing a race in usbhid.
      Signed-off-by: NOliver Neukum <oneukum@suse.de>
      Acked-by: NJiri Kosina <jkosina@suse.cz>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8815bb09
  12. 01 5月, 2012 2 次提交
  13. 30 4月, 2012 4 次提交
    • F
      usb: ch9: define Set SEL and Set Isoch Delay macros · 93c309de
      Felipe Balbi 提交于
      These are new requests introduced by USB 3.0
      Specification. Gadget controllers should implement
      them.
      Signed-off-by: NFelipe Balbi <balbi@ti.com>
      93c309de
    • G
      USB: remove CONFIG_USB_DEVICE_CLASS · 007bab91
      Greg Kroah-Hartman 提交于
      This option has been deprecated for many years now, and no userspace
      tools use it anymore, so it should be safe to finally remove it.
      Reported-by: NKay Sievers <kay@vrfy.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      007bab91
    • G
      USB: remove CONFIG_USB_DEVICEFS · fb28d58b
      Greg Kroah-Hartman 提交于
      This option has been deprecated for many years now, and no userspace
      tools use it anymore, so it should be safe to finally remove it.
      Reported-by: NKay Sievers <kay@vrfy.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fb28d58b
    • L
      pipes: add a "packetized pipe" mode for writing · 9883035a
      Linus Torvalds 提交于
      The actual internal pipe implementation is already really about
      individual packets (called "pipe buffers"), and this simply exposes that
      as a special packetized mode.
      
      When we are in the packetized mode (marked by O_DIRECT as suggested by
      Alan Cox), a write() on a pipe will not merge the new data with previous
      writes, so each write will get a pipe buffer of its own.  The pipe
      buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn
      will tell the reader side to break the read at that boundary (and throw
      away any partial packet contents that do not fit in the read buffer).
      
      End result: as long as you do writes less than PIPE_BUF in size (so that
      the pipe doesn't have to split them up), you can now treat the pipe as a
      packet interface, where each read() system call will read one packet at
      a time.  You can just use a sufficiently big read buffer (PIPE_BUF is
      sufficient, since bigger than that doesn't guarantee atomicity anyway),
      and the return value of the read() will naturally give you the size of
      the packet.
      
      NOTE! We do not support zero-sized packets, and zero-sized reads and
      writes to a pipe continue to be no-ops.  Also note that big packets will
      currently be split at write time, but that the size at which that
      happens is not really specified (except that it's bigger than PIPE_BUF).
      Currently that limit is the system page size, but we might want to
      explicitly support bigger packets some day.
      
      The main user for this is going to be the autofs packet interface,
      allowing us to stop having to care so deeply about exact packet sizes
      (which have had bugs with 32/64-bit compatibility modes).  But user
      space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will
      fail with an EINVAL on kernels that do not support this interface.
      Tested-by: NMichael Tokarev <mjt@tls.msk.ru>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: David Miller <davem@davemloft.net>
      Cc: Ian Kent <raven@themaw.net>
      Cc: Thomas Meyer <thomas@m3y3r.de>
      Cc: stable@kernel.org  # needed for systemd/autofs interaction fix
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9883035a
  14. 28 4月, 2012 1 次提交
  15. 27 4月, 2012 1 次提交
  16. 26 4月, 2012 2 次提交
  17. 25 4月, 2012 1 次提交
    • A
      USB: EHCI: fix crash during suspend on ASUS computers · 151b6128
      Alan Stern 提交于
      This patch (as1545) 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.
      
      This fixes Bugzilla #42728.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Tested-by: NSteven Rostedt <rostedt@goodmis.org>
      Tested-by: NAndrey Rahmatullin <wrar@wrar.name>
      Tested-by: NOleksij Rempel (fishor) <bug-track@fisher-privat.net>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      151b6128
  18. 24 4月, 2012 1 次提交
  19. 23 4月, 2012 2 次提交