1. 19 9月, 2013 2 次提交
  2. 18 9月, 2013 3 次提交
  3. 17 9月, 2013 10 次提交
    • R
      MIPS: Fix accessing to per-cpu data when flushing the cache · ff522058
      Ralf Baechle 提交于
      This fixes the following issue
      
      BUG: using smp_processor_id() in preemptible [00000000] code: kjournald/1761
      caller is blast_dcache32+0x30/0x254
      Call Trace:
      [<8047f02c>] dump_stack+0x8/0x34
      [<802e7e40>] debug_smp_processor_id+0xe0/0xf0
      [<80114d94>] blast_dcache32+0x30/0x254
      [<80118484>] r4k_dma_cache_wback_inv+0x200/0x288
      [<80110ff0>] mips_dma_map_sg+0x108/0x180
      [<80355098>] ide_dma_prepare+0xf0/0x1b8
      [<8034eaa4>] do_rw_taskfile+0x1e8/0x33c
      [<8035951c>] ide_do_rw_disk+0x298/0x3e4
      [<8034a3c4>] do_ide_request+0x2e0/0x704
      [<802bb0dc>] __blk_run_queue+0x44/0x64
      [<802be000>] queue_unplugged.isra.36+0x1c/0x54
      [<802beb94>] blk_flush_plug_list+0x18c/0x24c
      [<802bec6c>] blk_finish_plug+0x18/0x48
      [<8026554c>] journal_commit_transaction+0x3b8/0x151c
      [<80269648>] kjournald+0xec/0x238
      [<8014ac00>] kthread+0xb8/0xc0
      [<8010268c>] ret_from_kernel_thread+0x14/0x1c
      
      Caches in most systems are identical - but not always, so we can't avoid
      the use of smp_call_function() by just looking at the boot CPU's data,
      have to fiddle with preemption instead.
      Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      Cc: Markos Chandras <markos.chandras@imgtec.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/5835
      ff522058
    • R
      MIPS: Provide nice way to access boot CPU's data. · c5f66596
      Ralf Baechle 提交于
      boot_cpu_data is used the same as current_cpu_data but returns the CPU
      data for CPU 0.  This means it doesn't have to use smp_processor_id()
      thus no need to disable preemption.
      Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      c5f66596
    • A
      staging: octeon-ethernet: rgmii: enable interrupts that we can handle · 7cc4fa1e
      Aaro Koskinen 提交于
      Enable only those interrupts that we can handle & acknowledge in the
      interrupt handler.
      
      At least on EdgeRouter Lite, the hardware may occasionally interrupt with
      some error condition when the physical link status changes frequently.
      Since the interrupt condition is not acked properly, this leads to the
      following warning and the IRQ gets disabled completely:
      
      [   41.324700] eth0: Link down
      [   44.324721] eth0: 1000 Mbps Full duplex, port  0, queue  0
      [   44.885590] irq 117: nobody cared (try booting with the "irqpoll" option)
      [   44.892397] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.11.0-rc5-edge-los.git-27d042f-dirty-00950-gaa42f2d-dirty #8
      [   44.902825] Stack : ffffffff815c0000 0000000000000004 0000000000000003 0000000000000000
      	  ffffffff81fd0000 ffffffff815c0000 0000000000000004 ffffffff8118530c
      	  ffffffff815c0000 ffffffff811858d8 0000000000000000 0000000000000000
      	  ffffffff81fd0000 ffffffff81fc0000 ffffffff8152f3a0 ffffffff815b7bf7
      	  ffffffff81fc6688 ffffffff815b8060 0000000000000000 0000000000000000
      	  0000000000000000 ffffffff815346c8 ffffffff815346b0 ffffffff814a6a18
      	  ffffffff8158b848 ffffffff81145614 ffffffff81593800 ffffffff81187174
      	  ffffffff815b7d00 ffffffff8158b760 0000000000000000 ffffffff814a9184
      	  0000000000000000 0000000000000000 0000000000000000 0000000000000000
      	  0000000000000000 ffffffff811203b8 0000000000000000 0000000000000000
      	  ...
      [   44.968408] Call Trace:
      [   44.970873] [<ffffffff811203b8>] show_stack+0x68/0x80
      [   44.975937] [<ffffffff814a9184>] dump_stack+0x78/0xb8
      [   44.980999] [<ffffffff811aac54>] __report_bad_irq+0x44/0x108
      [   44.986662] [<ffffffff811ab238>] note_interrupt+0x248/0x2a0
      [   44.992240] [<ffffffff811a85e4>] handle_irq_event_percpu+0x144/0x200
      [   44.998598] [<ffffffff811a86f4>] handle_irq_event+0x54/0x90
      [   45.004176] [<ffffffff811ab908>] handle_level_irq+0xd0/0x148
      [   45.009839] [<ffffffff811a7b04>] generic_handle_irq+0x34/0x50
      [   45.015589] [<ffffffff8111dae8>] do_IRQ+0x18/0x30
      [   45.020301] [<ffffffff8110486c>] plat_irq_dispatch+0x74/0xb8
      [   45.025958]
      [   45.027451] handlers:
      [   45.029731] [<ffffffff813fca10>] cvm_oct_rgmii_rml_interrupt
      [   45.035397] Disabling IRQ #117
      [   45.038742] Port 0 receive error code 13, packet dropped
      [   46.324719] eth0: Link down
      [   48.324733] eth0: 1000 Mbps Full duplex, port  0, queue  0
      Reported-by: N"Jason A. Donenfeld" <Jason@zx2c4.com>
      Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
      Acked-by: NDavid Daney <david.daney@cavium.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: devel@driverdev.osuosl.org
      Cc: linux-mips@linux-mips.org
      Cc: Jason A. Donenfeld <Jason@zx2c4.com>
      Cc: richard@nod.at
      Patchwork: https://patchwork.linux-mips.org/patch/5810/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      7cc4fa1e
    • A
      staging: octeon-ethernet: remove skb alloc failure warnings · a5de43c1
      Aaro Koskinen 提交于
      Remove skb allocation failure warnings. They will trigger a page
      allocation warning already. Also, one of the warnings was not ratelimited,
      causing the box to lock up under heavy traffic & low memory.
      Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
      Acked-by: NDavid Daney <david.daney@cavium.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: devel@driverdev.osuosl.org
      Cc: linux-mips@linux-mips.org
      Cc: Jason A. Donenfeld <Jason@zx2c4.com>
      Cc: richard@nod.at
      Cc: Aaro Koskinen <aaro.koskinen@iki.fi>
      Patchwork: https://patchwork.linux-mips.org/patch/5811/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      a5de43c1
    • A
      staging: octeon-ethernet: make dropped packets to consume NAPI budget · da029d0c
      Aaro Koskinen 提交于
      We should count also dropped packets, otherwise the NAPI handler may
      end up running too long.
      Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: devel@driverdev.osuosl.org
      Cc: linux-mips@linux-mips.org
      Cc: David Daney <david.daney@cavium.com>
      Cc: Jason A. Donenfeld <Jason@zx2c4.com>
      Cc: richard@nod.at
      Patchwork: https://patchwork.linux-mips.org/patch/5809/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      da029d0c
    • L
      Linux 3.12-rc1 · 272b98c6
      Linus Torvalds 提交于
      272b98c6
    • L
      Merge branch 'timers/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip · a4ae54f9
      Linus Torvalds 提交于
      Pull timer code update from Thomas Gleixner:
       - armada SoC clocksource overhaul with a trivial merge conflict
       - Minor improvements to various SoC clocksource drivers
      
      * 'timers/core' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
        clocksource: armada-370-xp: Add detailed clock requirements in devicetree binding
        clocksource: armada-370-xp: Get reference fixed-clock by name
        clocksource: armada-370-xp: Replace WARN_ON with BUG_ON
        clocksource: armada-370-xp: Fix device-tree binding
        clocksource: armada-370-xp: Introduce new compatibles
        clocksource: armada-370-xp: Use CLOCKSOURCE_OF_DECLARE
        clocksource: armada-370-xp: Simplify TIMER_CTRL register access
        clocksource: armada-370-xp: Use BIT()
        ARM: timer-sp: Set dynamic irq affinity
        ARM: nomadik: add dynamic irq flag to the timer
        clocksource: sh_cmt: 32-bit control register support
        clocksource: em_sti: Convert to devm_* managed helpers
      a4ae54f9
    • L
      Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6 · 3369d116
      Linus Torvalds 提交于
      Pull CIFS fixes from Steve French:
       "Two minor cifs fixes and a minor documentation cleanup for cifs.txt"
      
      * 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
        cifs: update cifs.txt and remove some outdated infos
        cifs: Avoid calling unlock_page() twice in cifs_readpage() when using fscache
        cifs: Do not take a reference to the page in cifs_readpage_worker()
      3369d116
    • L
      Merge tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubi · f1da3458
      Linus Torvalds 提交于
      Pull UBI fixes from Artem Bityutskiy:
       "Just a single fastmap fix plus a regression fix"
      
      * tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubi:
        UBI: Fix invalidate_fastmap()
        UBI: Fix PEB leak in wear_leveling_worker()
      f1da3458
    • L
      Merge tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifs · 098e7f16
      Linus Torvalds 提交于
      Pull ubifs fix from Artem Bityutskiy:
       "Just one patch which fixes the power-cut recovery testing mode.
      
        I'll start using a single UBI/UBIFS tree instead of 2 trees from now
        on.  So in the future you'll get 1 small pull request instead of 2
        tiny ones"
      
      * tag 'upstream-3.12-rc1' of git://git.infradead.org/linux-ubifs:
        UBIFS: remove invalid warn msg with tst_recovery enabled
      098e7f16
  4. 16 9月, 2013 3 次提交
    • L
      Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus · d8efd82e
      Linus Torvalds 提交于
      Pull MIPS fixes from Ralf Baechle:
       "These are four patches for three construction sites:
      
         - Fix register decoding for the combination of multi-core processors
           and multi-threading.
      
         - Two more fixes that are part of the ongoing DECstation resurrection
           work.  One of these touches a DECstation-only network driver.
      
         - Finally Markos' trivial build fix for the AP/SP support.
      
        (With this applied now all MIPS defconfigs are building again)"
      
      * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
        MIPS: kernel: vpe: Make vpe_attrs an array of pointers.
        MIPS: Fix SMP core calculations when using MT support.
        MIPS: DECstation I/O ASIC DMA interrupt handling fix
        MIPS: DECstation HRT initialization rearrangement
      d8efd82e
    • L
      Merge branch 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86 · cd619e21
      Linus Torvalds 提交于
      Pull x86 platform updates from Matthew Garrett:
       "Nothing amazing here, almost entirely cleanups and minor bugfixes and
        one bit of hardware enablement in the amilo-rfkill driver"
      
      * 'for_linus' of git://cavan.codon.org.uk/platform-drivers-x86:
        platform/x86: panasonic-laptop: reuse module_acpi_driver
        samsung-laptop: fix config build error
        platform: x86: remove unnecessary platform_set_drvdata()
        amilo-rfkill: Enable using amilo-rfkill with the FSC Amilo L1310.
        wmi: parse_wdg() should return kernel error codes
        hp_wmi: Fix unregister order in hp_wmi_rfkill_setup()
        platform: replace strict_strto*() with kstrto*()
        x86: irst: use module_acpi_driver to simplify the code
        x86: smartconnect: use module_acpi_driver to simplify the code
        platform samsung-q10: use ACPI instead of direct EC calls
        thinkpad_acpi: add the ability setting TPACPI_LED_NONE by quirk
        thinkpad_acpi: return -NODEV while operating uninitialized LEDs
      cd619e21
    • L
      Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi · 0375ec58
      Linus Torvalds 提交于
      Pull misc SCSI driver updates from James Bottomley:
       "This patch set is a set of driver updates (megaraid_sas, fnic, lpfc,
        ufs, hpsa) we also have a couple of bug fixes (sd out of bounds and
        ibmvfc error handling) and the first round of esas2r checker fixes and
        finally the much anticipated big endian additions for megaraid_sas"
      
      * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (47 commits)
        [SCSI] fnic: fnic Driver Tuneables Exposed through CLI
        [SCSI] fnic: Kernel panic while running sh/nosh with max lun cfg
        [SCSI] fnic: Hitting BUG_ON(io_req->abts_done) in fnic_rport_exch_reset
        [SCSI] fnic: Remove QUEUE_FULL handling code
        [SCSI] fnic: On system with >1.1TB RAM, VIC fails multipath after boot up
        [SCSI] fnic: FC stat param seconds_since_last_reset not getting updated
        [SCSI] sd: Fix potential out-of-bounds access
        [SCSI] lpfc 8.3.42: Update lpfc version to driver version 8.3.42
        [SCSI] lpfc 8.3.42: Fixed issue of task management commands having a fixed timeout
        [SCSI] lpfc 8.3.42: Fixed inconsistent spin lock usage.
        [SCSI] lpfc 8.3.42: Fix driver's abort loop functionality to skip IOs already getting aborted
        [SCSI] lpfc 8.3.42: Fixed failure to allocate SCSI buffer on PPC64 platform for SLI4 devices
        [SCSI] lpfc 8.3.42: Fix WARN_ON when driver unloads
        [SCSI] lpfc 8.3.42: Avoided making pci bar ioremap call during dual-chute WQ/RQ pci bar selection
        [SCSI] lpfc 8.3.42: Fixed driver iocbq structure's iocb_flag field running out of space
        [SCSI] lpfc 8.3.42: Fix crash on driver load due to cpu affinity logic
        [SCSI] lpfc 8.3.42: Fixed logging format of setting driver sysfs attributes hard to interpret
        [SCSI] lpfc 8.3.42: Fixed back to back RSCNs discovery failure.
        [SCSI] lpfc 8.3.42: Fixed race condition between BSG I/O dispatch and timeout handling
        [SCSI] lpfc 8.3.42: Fixed function mode field defined too small for not recognizing dual-chute mode
        ...
      0375ec58
  5. 15 9月, 2013 4 次提交
  6. 14 9月, 2013 8 次提交
  7. 13 9月, 2013 10 次提交
    • L
      Merge branch 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux · 399a946e
      Linus Torvalds 提交于
      Pull generic hardirq option removal from Martin Schwidefsky:
       "All architectures now use generic hardirqs, s390 has been last to
        switch.
      
        With that the code under !CONFIG_GENERIC_HARDIRQS and the related
        HAVE_GENERIC_HARDIRQS and GENERIC_HARDIRQS config options can be
        removed.  Yay!"
      
      * 'genirq' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
        Remove GENERIC_HARDIRQ config option
      399a946e
    • L
      Merge branch 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild · 183c4203
      Linus Torvalds 提交于
      Pull kconfig fix from Michal Marek:
       "This is a fix for a regression caused by my previous pull request.
      
        A sed command in scripts/config that used colons as separator was
        accidentally changed to use slashes, which fails when you use slashes
        in a value.  Changing it back to colons is of course not a proper fix,
        but at least it will be broken in the same way it had been for four
        years.  A proper fix is pending"
      
      * 'kconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
        scripts/config: fix variable substitution command
      183c4203
    • L
      Merge tag 'blackfin-for-linus' of... · 951a730a
      Linus Torvalds 提交于
      Merge tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux
      
      Pull blackfin updates from Steven Miao.
      
      * tag 'blackfin-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/realmz6/blackfin-linux:
        blackfin: Ignore generated uImages
        blackfin: Add STMMAC platform data to enable dwmac1000 driver on BF60x.
        bf609: adv7343: add S-Video and Component output support
        bf609: add adv7343 video encoder support
        clock: add stmmac clock for ethernet driver
        blackfin: scb: Add SCB1 to SCB9 config options and data.
        blackfin: scb: Add system crossbar init code.
      951a730a
    • L
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 · 0898d2aa
      Linus Torvalds 提交于
      Pull crypto fixes from Herbert Xu:
       "This fixes a 7+ year race condition in the crypto API that causes
        sporadic crashes when multiple threads load the same algorithm.
      
        It also fixes the crct10dif algorithm again to prevent boot failures
        on systems where the initramfs tool ignores module softdeps"
      
      * git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
        crypto: crct10dif - Add fallback for broken initrds
        crypto: api - Fix race condition in larval lookup
      0898d2aa
    • M
      MIPS: kernel: vpe: Make vpe_attrs an array of pointers. · 1b467633
      Markos Chandras 提交于
      Commit 567b21e9
      "mips: convert vpe_class to use dev_groups"
      
      broke the build on MIPS since vpe_attrs should be an array
      of 'struct device_attribute' pointers.
      
      Fixes the following build problem:
      arch/mips/kernel/vpe.c:1372:2: error: missing braces around initializer
      [-Werror=missing-braces]
      arch/mips/kernel/vpe.c:1372:2: error: (near initialization for 'vpe_attrs[0]')
      [-Werror=missing-braces]
      
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: John Crispin <blogic@openwrt.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Signed-off-by: NMarkos Chandras <markos.chandras@imgtec.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/5819/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      1b467633
    • M
      Remove GENERIC_HARDIRQ config option · 0244ad00
      Martin Schwidefsky 提交于
      After the last architecture switched to generic hard irqs the config
      options HAVE_GENERIC_HARDIRQS & GENERIC_HARDIRQS and the related code
      for !CONFIG_GENERIC_HARDIRQS can be removed.
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      0244ad00
    • C
      scripts/config: fix variable substitution command · 86eb7818
      Clement Chauplannaz 提交于
      Commit 229455bc02b87f7128f190c4491b4ceffff38648 accidentally changed the
      separator between sed `s' command and its parameters from ':' to '/'.
      
      Revert this change.
      Reported-and-tested-by: NLinus Walleij <linus.walleij@linaro.org>
      Signed-off-by: NClement Chauplannaz <chauplac@gmail.com>
      Signed-off-by: NMichal Marek <mmarek@suse.cz>
      86eb7818
    • L
      MIPS: Fix SMP core calculations when using MT support. · 670bac3a
      Leonid Yegoshin 提交于
      The TCBIND register is only available if the core has MT support. It
      should not be read otherwise. Secondly, the number of TCs (siblings)
      are calculated differently depending on if the kernel is configured
      as SMVP or SMTC.
      Signed-off-by: NLeonid Yegoshin <Leonid.Yegoshin@imgtec.com>
      Signed-off-by: NSteven J. Hill <Steven.Hill@imgtec.com>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/5822/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      670bac3a
    • M
      MIPS: DECstation I/O ASIC DMA interrupt handling fix · 5359b938
      Maciej W. Rozycki 提交于
      This change complements commit d0da7c002f7b2a93582187a9e3f73891a01d8ee4
      and brings clear_ioasic_irq back, renaming it to clear_ioasic_dma_irq at
      the same time, to make I/O ASIC DMA interrupts functional.
      
      Unlike ordinary I/O ASIC interrupts DMA interrupts need to be deasserted
      by software by writing 0 to the respective bit in I/O ASIC's System
      Interrupt Register (SIR), similarly to how CP0.Cause.IP0 and CP0.Cause.IP1
      bits are handled in the CPU (the difference is SIR DMA interrupt bits are
      R/W0C so there's no need for an RMW cycle).  Otherwise the handler is
      reentered over and over again.
      
      The only current user is the DEC LANCE Ethernet driver and its extremely
      uncommon DMA memory error handler that does not care when exactly the
      interrupt is cleared.  Anticipating the use of DMA interrupts by the Zilog
      SCC driver this change however exports clear_ioasic_dma_irq for device
      drivers to choose the right application-specific sequence to clear the
      request explicitly rather than calling it implicitly in the .irq_eoi
      handler of `struct irq_chip'.  Previously these interrupts were cleared in
      the .end handler of the said structure, before it was removed.
      Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/5826/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      5359b938
    • M
      MIPS: DECstation HRT initialization rearrangement · daed1285
      Maciej W. Rozycki 提交于
      Not all I/O ASIC versions have the free-running counter implemented, an
      early revision used in the 5000/1xx models aka 3MIN and 4MIN did not have
      it.  Therefore we cannot unconditionally use it as a clock source.
      Fortunately if not implemented its register slot has a fixed value so it
      is enough if we check for the value at the end of the calibration period
      being the same as at the beginning.
      
      This also means we need to look for another high-precision clock source on
      the systems affected.  The 5000/1xx can have an R4000SC processor
      installed where the CP0 Count register can be used as a clock source.
      Unfortunately all the R4k DECstations suffer from the missed timer
      interrupt on CP0 Count reads erratum, so we cannot use the CP0 timer as a
      clock source and a clock event both at a time.  However we never need an
      R4k clock event device because all DECstations have a DS1287A RTC chip
      whose periodic interrupt can be used as a clock source.
      
      This gives us the following four configuration possibilities for I/O ASIC
      DECstations:
      
      1. No I/O ASIC counter and no CP0 timer, e.g. R3k 5000/1xx (3MIN).
      
      2. No I/O ASIC counter but the CP0 timer, i.e. R4k 5000/150 (4MIN).
      
      3. The I/O ASIC counter but no CP0 timer, e.g. R3k 5000/240 (3MAX+).
      
      4. The I/O ASIC counter and the CP0 timer, e.g. R4k 5000/260 (4MAX+).
      
      For #1 and #2 this change stops the I/O ASIC free-running counter from
      being installed as a clock source of a 0Hz frequency.  For #2 it also
      arranges for the CP0 timer to be used as a clock source rather than a
      clock event device, because having an accurate wall clock is more
      important than a high-precision interval timer.  For #3 there is no
      change.  For #4 the change makes the I/O ASIC free-running counter
      installed as a clock source so that the CP0 timer can be used as a clock
      event device.
      
      Unfortunately the use of the CP0 timer as a clock event device relies on a
      succesful completion of c0_compare_interrupt.  That never happens, because
      while waiting for a CP0 Compare interrupt to happen the function spins in
      a loop reading the CP0 Count register.  This makes the CP0 Count erratum
      trigger reliably causing the interrupt waited for to be lost in all cases.
      As a result #4 resorts to using the CP0 timer as a clock source as well,
      just as #2.  However we want to keep this separate arrangement in case
      (hope) c0_compare_interrupt is eventually rewritten such that it avoids
      the erratum.
      Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
      Cc: linux-mips@linux-mips.org
      Patchwork: https://patchwork.linux-mips.org/patch/5825/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
      daed1285