Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
[muen/linux.git] / Documentation / admin-guide / kernel-parameters.txt
index e0d82520668103d863b2a417caeb67897b4734f7..34dac7cef4cfbfd8b4c59d4996b81f14a4c45f87 100644 (file)
                        console=brl,ttyS0
                For now, only VisioBraille is supported.
 
+       console_msg_format=
+                       [KNL] Change console messages format
+               default
+                       By default we print messages on consoles in
+                       "[time stamp] text\n" format (time stamp may not be
+                       printed, depending on CONFIG_PRINTK_TIME or
+                       `printk_time' param).
+               syslog
+                       Switch to syslog format: "<%u>[time stamp] text\n"
+                       IOW, each message will have a facility and loglevel
+                       prefix. The format is similar to one used by syslog()
+                       syscall, or to executing "dmesg -S --raw" or to reading
+                       from /proc/kmsg.
+
        consoleblank=   [KNL] The console blank (screen saver) timeout in
                        seconds. A value of 0 disables the blank timer.
                        Defaults to 0.
 
        earlycon=       [KNL] Output early console device and options.
 
-                       When used with no options, the early console is
-                       determined by the stdout-path property in device
-                       tree's chosen node.
+                       [ARM64] The early console is determined by the
+                       stdout-path property in device tree's chosen node,
+                       or determined by the ACPI SPCR table.
+
+                       [X86] When used with no options the early console is
+                       determined by the ACPI SPCR table.
 
                cdns,<addr>[,options]
                        Start an early, polled-mode console on a Cadence
                        address. The serial port must already be setup
                        and configured. Options are not yet supported.
 
-       earlyprintk=    [X86,SH,BLACKFIN,ARM,M68k,S390]
+       earlyprintk=    [X86,SH,ARM,M68k,S390]
                        earlyprintk=vga
                        earlyprintk=efi
                        earlyprintk=sclp
                               If specified, z/VM IUCV HVC accepts connections
                               from listed z/VM user IDs only.
 
-       hwthread_map=   [METAG] Comma-separated list of Linux cpu id to
-                               hardware thread id mappings.
-                               Format: <cpu>:<hwthread>
-
        keep_bootcon    [KNL]
                        Do not unregister boot console at start. This is only
                        useful for debugging when something happens in the window
                        of a GICv2 controller even if the memory range
                        exposed by the device tree is too small.
 
+       irqchip.gicv3_nolpi=
+                       [ARM, ARM64]
+                       Force the kernel to ignore the availability of
+                       LPIs (and by consequence ITSs). Intended for system
+                       that use the kernel as a bootloader, and thus want
+                       to let secondary kernels in charge of setting up
+                       LPIs.
+
        irqfixup        [HW]
                        When an interrupt is not handled search all handlers
                        for it. Intended to get systems with badly broken
 
                        nohz
                          Disable the tick when a single task runs.
+
+                         A residual 1Hz tick is offloaded to workqueues, which you
+                         need to affine to housekeeping through the global
+                         workqueue's affinity configured via the
+                         /sys/devices/virtual/workqueue/cpumask sysfs file, or
+                         by using the 'domain' flag described below.
+
+                         NOTE: by default the global workqueue runs on all CPUs,
+                         so to protect individual CPUs the 'cpumask' file has to
+                         be configured manually after bootup.
+
                        domain
                          Isolate from the general SMP balancing and scheduling
                          algorithms. Note that performing domain isolation this way
                        The memory region may be marked as e820 type 12 (0xc)
                        and is NVDIMM or ADR memory.
 
+       memmap=<size>%<offset>-<oldtype>+<newtype>
+                       [KNL,ACPI] Convert memory within the specified region
+                       from <oldtype> to <newtype>. If "-<oldtype>" is left
+                       out, the whole region will be marked as <newtype>,
+                       even if previously unavailable. If "+<newtype>" is left
+                       out, matching memory will be removed. Types are
+                       specified as e820 types, e.g., 1 = RAM, 2 = reserved,
+                       3 = ACPI, 12 = PRAM.
+
        memory_corruption_check=0/1 [X86]
                        Some BIOSes seem to corrupt the first 64k of
                        memory when doing things like suspend/resume.
                        This is useful when you use a panic=... timeout and
                        need the box quickly up again.
 
+                       These settings can be accessed at runtime via
+                       the nmi_watchdog and hardlockup_panic sysctls.
+
        netpoll.carrier_timeout=
                        [NET] Specifies amount of time (in seconds) that
                        netpoll should wait for a carrier. By default netpoll
        norandmaps      Don't use address space randomization.  Equivalent to
                        echo 0 > /proc/sys/kernel/randomize_va_space
 
-       noreplace-paravirt      [X86,IA-64,PV_OPS] Don't patch paravirt_ops
-
        noreplace-smp   [X86-32,SMP] Don't replace SMP instructions
                        with UP alternatives
 
                        [KNL, SMP] Set scheduler's default relax_domain_level.
                        See Documentation/cgroup-v1/cpusets.txt.
 
-       reserve=        [KNL,BUGS] Force the kernel to ignore some iomem area
+       reserve=        [KNL,BUGS] Force kernel to ignore I/O ports or memory
+                       Format: <base1>,<size1>[,<base2>,<size2>,...]
+                       Reserve I/O ports or memory so the kernel won't use
+                       them.  If <base> is less than 0x10000, the region
+                       is assumed to be I/O ports; otherwise it is memory.
 
        reservetop=     [X86-32]
                        Format: nn[KMG]
 
        usbcore.nousb   [USB] Disable the USB subsystem
 
+       usbcore.quirks=
+                       [USB] A list of quirk entries to augment the built-in
+                       usb core quirk list. List entries are separated by
+                       commas. Each entry has the form
+                       VendorID:ProductID:Flags. The IDs are 4-digit hex
+                       numbers and Flags is a set of letters. Each letter
+                       will change the built-in quirk; setting it if it is
+                       clear and clearing it if it is set. The letters have
+                       the following meanings:
+                               a = USB_QUIRK_STRING_FETCH_255 (string
+                                       descriptors must not be fetched using
+                                       a 255-byte read);
+                               b = USB_QUIRK_RESET_RESUME (device can't resume
+                                       correctly so reset it instead);
+                               c = USB_QUIRK_NO_SET_INTF (device can't handle
+                                       Set-Interface requests);
+                               d = USB_QUIRK_CONFIG_INTF_STRINGS (device can't
+                                       handle its Configuration or Interface
+                                       strings);
+                               e = USB_QUIRK_RESET (device can't be reset
+                                       (e.g morph devices), don't use reset);
+                               f = USB_QUIRK_HONOR_BNUMINTERFACES (device has
+                                       more interface descriptions than the
+                                       bNumInterfaces count, and can't handle
+                                       talking to these interfaces);
+                               g = USB_QUIRK_DELAY_INIT (device needs a pause
+                                       during initialization, after we read
+                                       the device descriptor);
+                               h = USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL (For
+                                       high speed and super speed interrupt
+                                       endpoints, the USB 2.0 and USB 3.0 spec
+                                       require the interval in microframes (1
+                                       microframe = 125 microseconds) to be
+                                       calculated as interval = 2 ^
+                                       (bInterval-1).
+                                       Devices with this quirk report their
+                                       bInterval as the result of this
+                                       calculation instead of the exponent
+                                       variable used in the calculation);
+                               i = USB_QUIRK_DEVICE_QUALIFIER (device can't
+                                       handle device_qualifier descriptor
+                                       requests);
+                               j = USB_QUIRK_IGNORE_REMOTE_WAKEUP (device
+                                       generates spurious wakeup, ignore
+                                       remote wakeup capability);
+                               k = USB_QUIRK_NO_LPM (device can't handle Link
+                                       Power Management);
+                               l = USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL
+                                       (Device reports its bInterval as linear
+                                       frames instead of the USB 2.0
+                                       calculation);
+                               m = USB_QUIRK_DISCONNECT_SUSPEND (Device needs
+                                       to be disconnected before suspend to
+                                       prevent spurious wakeup);
+                               n = USB_QUIRK_DELAY_CTRL_MSG (Device needs a
+                                       pause after every control message);
+                       Example: quirks=0781:5580:bk,0a5c:5834:gij
+
        usbhid.mousepoll=
                        [USBHID] The interval which mice are to be polled at.