1. 29 Sep, 2014 4 commits
    • Bryan O'Donoghue's avatar
      serial: 8250: Add Quark X1000 to 8250_pci.c · 1ede7dcc
      Bryan O'Donoghue authored
      Quark X1000 contains two designware derived 8250 serial ports.
      Each port has a unique PCI configuration space consisting of
      BAR0:UART BAR1:DMA respectively.
      
      Unlike the standard 8250 the register width is 32 bits for RHR,IER etc
      The Quark UART has a fundamental clock @ 44.2368 MHz allowing for a
      bitrate of up to about 2.76 megabits per second.
      
      This patch enables standard 8250 mode
      Signed-off-by: default avatarBryan O'Donoghue <pure.logic@nexus-software.ie>
      Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      1ede7dcc
    • Frans Klaver's avatar
      tty: omap-serial: pull out calculation from baud_is_mode16 · 13d6ceb4
      Frans Klaver authored
      To determine the correct divisor, we need to know the difference between
      the desired baud rate and the actual baud rate. The calculation for this
      difference is implemented twice within omap_serial_baud_is_mode16().
      Pull out the calculation for easier maintenance.
      
      While at it, remove the CamelCasing from the variable names.
      Signed-off-by: default avatarFrans Klaver <frans.klaver@xsens.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      13d6ceb4
    • Frans Klaver's avatar
      tty: omap-serial: fix division by zero · dc318756
      Frans Klaver authored
      If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
      calculated n values in serial_omap_is_baud_mode16() may become 0. This
      causes a division by zero when calculating the difference between
      calculated and desired baud rates. To prevent this, cap the n13 and n16
      values on 1.
      
      Division by zero in kernel.
      [<c00132e0>] (unwind_backtrace) from [<c00112ec>] (show_stack+0x10/0x14)
      [<c00112ec>] (show_stack) from [<c01ed7bc>] (Ldiv0+0x8/0x10)
      [<c01ed7bc>] (Ldiv0) from [<c023805c>] (serial_omap_baud_is_mode16+0x4c/0x68)
      [<c023805c>] (serial_omap_baud_is_mode16) from [<c02396b4>] (serial_omap_set_termios+0x90/0x8d8)
      [<c02396b4>] (serial_omap_set_termios) from [<c0230a0c>] (uart_change_speed+0xa4/0xa8)
      [<c0230a0c>] (uart_change_speed) from [<c0231798>] (uart_set_termios+0xa0/0x1fc)
      [<c0231798>] (uart_set_termios) from [<c022bb44>] (tty_set_termios+0x248/0x2c0)
      [<c022bb44>] (tty_set_termios) from [<c022c17c>] (set_termios+0x248/0x29c)
      [<c022c17c>] (set_termios) from [<c022c3e4>] (tty_mode_ioctl+0x1c8/0x4e8)
      [<c022c3e4>] (tty_mode_ioctl) from [<c0227e70>] (tty_ioctl+0xa94/0xb18)
      [<c0227e70>] (tty_ioctl) from [<c00cf45c>] (do_vfs_ioctl+0x4a0/0x560)
      [<c00cf45c>] (do_vfs_ioctl) from [<c00cf568>] (SyS_ioctl+0x4c/0x74)
      [<c00cf568>] (SyS_ioctl) from [<c000e480>] (ret_fast_syscall+0x0/0x30)
      Signed-off-by: default avatarFrans Klaver <frans.klaver@xsens.com>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dc318756
    • Stefano Stabellini's avatar
      xen_hvc: no reason to write the type key on xenstore · fb498df0
      Stefano Stabellini authored
      The backend type is chosen by the toolstack. Regardless, the frontend
      should not care, especially given that it cannot have an effect as the
      backend is started before this code is run.
      Signed-off-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      fb498df0
  2. 26 Sep, 2014 5 commits
    • Sebastian Andrzej Siewior's avatar
      tty: serial: 8250_core: remove UART_IER_RDI in serial8250_stop_rx() · 9137568e
      Sebastian Andrzej Siewior authored
      serial8250_do_startup() adds UART_IER_RDI and UART_IER_RLSI to ier.
      serial8250_stop_rx() should remove both.
      This is what the serial-omap driver has been doing and is now moved to
      the 8250-core since it does no look to be *that* omap specific.
      Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
      Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
      Tested-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9137568e
    • Sebastian Andrzej Siewior's avatar
      tty: serial: 8250_core: use the ->line argument as a hint in serial8250_find_match_or_unused() · 59b3e898
      Sebastian Andrzej Siewior authored
      Tony noticed that the old omap-serial driver picked the uart "number"
      based on the hint given from device tree or platform device's id.
      The 8250 based omap driver doesn't do this because the core code does
      not honour the ->line argument which is passed by the driver.
      
      This patch aims to keep the same behaviour as with omap-serial. The
      function will first try to use the line suggested ->line argument and
      then fallback to the old strategy in case the port is taken.
      
      That means the the third uart will always be ttyS2 even if the previous
      two have not been enabled in DT.
      Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
      Tested-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      59b3e898
    • Sebastian Andrzej Siewior's avatar
      tty: serial: 8250_core: read only RX if there is something in the FIFO · 0aa525d1
      Sebastian Andrzej Siewior authored
      The serial8250_do_startup() function unconditionally clears the
      interrupts and for that it reads from the RX-FIFO without checking if
      there is a byte in the FIFO or not. This works fine on OMAP4+ HW like
      AM335x or DRA7.
      OMAP3630 ES1.1 (which means probably all OMAP3 and earlier) does not like
      this:
      
      |Unhandled fault: external abort on non-linefetch (0x1028) at 0xfb020000
      |Internal error: : 1028 [#1] ARM
      |Modules linked in:
      |CPU: 0 PID: 1 Comm: swapper Not tainted 3.16.0-00022-g7edcb57-dirty #1213
      |task: de0572c0 ti: de058000 task.ti: de058000
      |PC is at mem32_serial_in+0xc/0x1c
      |LR is at serial8250_do_startup+0x220/0x85c
      |Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
      |Control: 10c5387d  Table: 80004019  DAC: 00000015
      |[<c03051d4>] (mem32_serial_in) from [<c0307fe8>] (serial8250_do_startup+0x220/0x85c)
      |[<c0307fe8>] (serial8250_do_startup) from [<c0309e00>] (omap_8250_startup+0x5c/0xe0)
      |[<c0309e00>] (omap_8250_startup) from [<c030863c>] (serial8250_startup+0x18/0x2c)
      |[<c030863c>] (serial8250_startup) from [<c030394c>] (uart_startup+0x78/0x1d8)
      |[<c030394c>] (uart_startup) from [<c0304678>] (uart_open+0xe8/0x114)
      |[<c0304678>] (uart_open) from [<c02e9e10>] (tty_open+0x1a8/0x5a4)
      Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
      Tested-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0aa525d1
    • Sebastian Andrzej Siewior's avatar
      tty: serial: 8250_core: add run time pm · d74d5d1b
      Sebastian Andrzej Siewior authored
      While comparing the OMAP-serial and the 8250 part of this I noticed that
      the latter does not use run time-pm. Here are the pieces. It is
      basically a get before first register access and a last_busy + put after
      last access. This has to be enabled from userland _and_ UART_CAP_RPM is
      required for this.
      The runtime PM can usually work transparently in the background however
      there is one exception to this: After serial8250_tx_chars() completes
      there still may be unsent bytes in the FIFO (depending on CPU speed vs
      baud rate + flow control). Even if the TTY-buffer is empty we do not
      want RPM to disable the device because it won't send the remaining
      bytes. Instead we leave serial8250_tx_chars() with RPM enabled and wait
      for the FIFO empty interrupt. Once we enter serial8250_tx_chars() with
      an empty buffer we know that the FIFO is empty and since we are not going
      to send anything, we can disable the device.
      That xchg() is to ensure that serial8250_tx_chars() can be called
      multiple times and only the first invocation will actually invoke the
      runtime PM function. So that the last invocation of __stop_tx() will
      disable runtime pm.
      
      NOTE: do not enable RPM on the device unless you know what you do! If
      the device goes idle, it won't be woken up by incomming RX data _unless_
      there is a wakeup irq configured which is usually the RX pin configure
      for wakeup via the reset module. The RX activity will then wake up the
      device from idle. However the first character is garbage and lost. The
      following bytes will be received once the device is up in time. On the
      beagle board xm (omap3) it takes approx 13ms from the first wakeup byte
      until the first byte that is received properly if the device was in
      core-off.
      
      v5…v8:
      	- drop RPM from serial8250_set_mctrl() it will be used in
      	  restore path which already has RPM active and holds
      	  dev->power.lock
      v4…v5:
      	- add a wrapper around rpm function and introduce UART_CAP_RPM
      	  to ensure RPM put is invoked after the TX FIFO is empty.
      v3…v4:
      	- added runtime to the console code
      	- removed device_may_wakeup() from serial8250_set_sleep()
      
      Cc: mika.westerberg@linux.intel.com
      Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
      Tested-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      d74d5d1b
    • Sebastian Andrzej Siewior's avatar
      tty: serial: 8250_core: allow to set ->throttle / ->unthrottle callbacks · 234abab1
      Sebastian Andrzej Siewior authored
      The OMAP UART provides support for HW assisted flow control. What is
      missing is the support to throttle / unthrottle callbacks which are used
      by the omap-serial driver at the moment.
      This patch adds the callbacks. It should be safe to add them since they
      are only invoked from the serial_core (uart_throttle()) if the feature
      flags are set.
      Reviewed-by: default avatarTony Lindgren <tony@atomide.com>
      Tested-by: default avatarTony Lindgren <tony@atomide.com>
      Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      234abab1
  3. 25 Sep, 2014 1 commit
  4. 24 Sep, 2014 15 commits
  5. 20 Sep, 2014 1 commit
  6. 15 Sep, 2014 4 commits
    • Greg Kroah-Hartman's avatar
      Merge 3.17-rc5 into tty-next · 882ebfc2
      Greg Kroah-Hartman authored
      We want those fixes in here as well.
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      882ebfc2
    • Linus Torvalds's avatar
      Linux 3.17-rc5 · 9e82bf01
      Linus Torvalds authored
      9e82bf01
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs · 83373f70
      Linus Torvalds authored
      Pull vfs fixes from Al Viro:
       "double iput() on failure exit in lustre, racy removal of spliced
        dentries from ->s_anon in __d_materialise_dentry() plus a bunch of
        assorted RCU pathwalk fixes"
      
      The RCU pathwalk fixes end up fixing a couple of cases where we
      incorrectly dropped out of RCU walking, due to incorrect initialization
      and testing of the sequence locks in some corner cases.  Since dropping
      out of RCU walk mode forces the slow locked accesses, those corner cases
      slowed down quite dramatically.
      
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
        be careful with nd->inode in path_init() and follow_dotdot_rcu()
        don't bugger nd->seq on set_root_rcu() from follow_dotdot_rcu()
        fix bogus read_seqretry() checks introduced in b37199e6
        move the call of __d_drop(anon) into __d_materialise_unique(dentry, anon)
        [fix] lustre: d_make_root() does iput() on dentry allocation failure
      83373f70
    • Linus Torvalds's avatar
      vfs: avoid non-forwarding large load after small store in path lookup · 9226b5b4
      Linus Torvalds authored
      The performance regression that Josef Bacik reported in the pathname
      lookup (see commit 99d263d4 "vfs: fix bad hashing of dentries") made
      me look at performance stability of the dcache code, just to verify that
      the problem was actually fixed.  That turned up a few other problems in
      this area.
      
      There are a few cases where we exit RCU lookup mode and go to the slow
      serializing case when we shouldn't, Al has fixed those and they'll come
      in with the next VFS pull.
      
      But my performance verification also shows that link_path_walk() turns
      out to have a very unfortunate 32-bit store of the length and hash of
      the name we look up, followed by a 64-bit read of the combined hash_len
      field.  That screws up the processor store to load forwarding, causing
      an unnecessary hickup in this critical routine.
      
      It's caused by the ugly calling convention for the "hash_name()"
      function, and easily fixed by just making hash_name() fill in the whole
      'struct qstr' rather than passing it a pointer to just the hash value.
      
      With that, the profile for this function looks much smoother.
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9226b5b4
  7. 14 Sep, 2014 10 commits