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-rw-r--r--Documentation/block/biodoc.txt19
-rw-r--r--Documentation/driver-model/platform.txt59
-rw-r--r--Documentation/filesystems/pohmelfs/design_notes.txt5
-rw-r--r--Documentation/filesystems/pohmelfs/info.txt21
-rw-r--r--Documentation/filesystems/vfs.txt3
-rw-r--r--Documentation/kbuild/makefiles.txt10
-rw-r--r--Documentation/kernel-parameters.txt78
-rw-r--r--Documentation/lguest/.gitignore1
-rw-r--r--Documentation/lguest/lguest.txt11
-rw-r--r--Documentation/networking/bonding.txt2
-rw-r--r--Documentation/sound/alsa/HD-Audio.txt4
-rw-r--r--Documentation/spi/spi-summary6
12 files changed, 170 insertions, 49 deletions
diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt
index ecad6ee75705..6fab97ea7e6b 100644
--- a/Documentation/block/biodoc.txt
+++ b/Documentation/block/biodoc.txt
@@ -1040,23 +1040,21 @@ Front merges are handled by the binary trees in AS and deadline schedulers.
iii. Plugging the queue to batch requests in anticipation of opportunities for
merge/sort optimizations
-This is just the same as in 2.4 so far, though per-device unplugging
-support is anticipated for 2.5. Also with a priority-based i/o scheduler,
-such decisions could be based on request priorities.
-
Plugging is an approach that the current i/o scheduling algorithm resorts to so
that it collects up enough requests in the queue to be able to take
advantage of the sorting/merging logic in the elevator. If the
queue is empty when a request comes in, then it plugs the request queue
-(sort of like plugging the bottom of a vessel to get fluid to build up)
+(sort of like plugging the bath tub of a vessel to get fluid to build up)
till it fills up with a few more requests, before starting to service
the requests. This provides an opportunity to merge/sort the requests before
passing them down to the device. There are various conditions when the queue is
unplugged (to open up the flow again), either through a scheduled task or
could be on demand. For example wait_on_buffer sets the unplugging going
-(by running tq_disk) so the read gets satisfied soon. So in the read case,
-the queue gets explicitly unplugged as part of waiting for completion,
-in fact all queues get unplugged as a side-effect.
+through sync_buffer() running blk_run_address_space(mapping). Or the caller
+can do it explicity through blk_unplug(bdev). So in the read case,
+the queue gets explicitly unplugged as part of waiting for completion on that
+buffer. For page driven IO, the address space ->sync_page() takes care of
+doing the blk_run_address_space().
Aside:
This is kind of controversial territory, as it's not clear if plugging is
@@ -1067,11 +1065,6 @@ Aside:
multi-page bios being queued in one shot, we may not need to wait to merge
a big request from the broken up pieces coming by.
- Per-queue granularity unplugging (still a Todo) may help reduce some of the
- concerns with just a single tq_disk flush approach. Something like
- blk_kick_queue() to unplug a specific queue (right away ?)
- or optionally, all queues, is in the plan.
-
4.4 I/O contexts
I/O contexts provide a dynamically allocated per process data area. They may
be used in I/O schedulers, and in the block layer (could be used for IO statis,
diff --git a/Documentation/driver-model/platform.txt b/Documentation/driver-model/platform.txt
index 83009fdcbbc8..2e2c2ea90ceb 100644
--- a/Documentation/driver-model/platform.txt
+++ b/Documentation/driver-model/platform.txt
@@ -169,3 +169,62 @@ three different ways to find such a match:
be probed later if another device registers. (Which is OK, since
this interface is only for use with non-hotpluggable devices.)
+
+Early Platform Devices and Drivers
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The early platform interfaces provide platform data to platform device
+drivers early on during the system boot. The code is built on top of the
+early_param() command line parsing and can be executed very early on.
+
+Example: "earlyprintk" class early serial console in 6 steps
+
+1. Registering early platform device data
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The architecture code registers platform device data using the function
+early_platform_add_devices(). In the case of early serial console this
+should be hardware configuration for the serial port. Devices registered
+at this point will later on be matched against early platform drivers.
+
+2. Parsing kernel command line
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The architecture code calls parse_early_param() to parse the kernel
+command line. This will execute all matching early_param() callbacks.
+User specified early platform devices will be registered at this point.
+For the early serial console case the user can specify port on the
+kernel command line as "earlyprintk=serial.0" where "earlyprintk" is
+the class string, "serial" is the name of the platfrom driver and
+0 is the platform device id. If the id is -1 then the dot and the
+id can be omitted.
+
+3. Installing early platform drivers belonging to a certain class
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The architecture code may optionally force registration of all early
+platform drivers belonging to a certain class using the function
+early_platform_driver_register_all(). User specified devices from
+step 2 have priority over these. This step is omitted by the serial
+driver example since the early serial driver code should be disabled
+unless the user has specified port on the kernel command line.
+
+4. Early platform driver registration
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Compiled-in platform drivers making use of early_platform_init() are
+automatically registered during step 2 or 3. The serial driver example
+should use early_platform_init("earlyprintk", &platform_driver).
+
+5. Probing of early platform drivers belonging to a certain class
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The architecture code calls early_platform_driver_probe() to match
+registered early platform devices associated with a certain class with
+registered early platform drivers. Matched devices will get probed().
+This step can be executed at any point during the early boot. As soon
+as possible may be good for the serial port case.
+
+6. Inside the early platform driver probe()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+The driver code needs to take special care during early boot, especially
+when it comes to memory allocation and interrupt registration. The code
+in the probe() function can use is_early_platform_device() to check if
+it is called at early platform device or at the regular platform device
+time. The early serial driver performs register_console() at this point.
+
+For further information, see <linux/platform_device.h>.
diff --git a/Documentation/filesystems/pohmelfs/design_notes.txt b/Documentation/filesystems/pohmelfs/design_notes.txt
index 6d6db60d567d..dcf833587162 100644
--- a/Documentation/filesystems/pohmelfs/design_notes.txt
+++ b/Documentation/filesystems/pohmelfs/design_notes.txt
@@ -56,9 +56,10 @@ workloads and can fully utilize the bandwidth to the servers when doing bulk
data transfers.
POHMELFS clients operate with a working set of servers and are capable of balancing read-only
-operations (like lookups or directory listings) between them.
+operations (like lookups or directory listings) between them according to IO priorities.
Administrators can add or remove servers from the set at run-time via special commands (described
-in Documentation/pohmelfs/info.txt file). Writes are replicated to all servers.
+in Documentation/pohmelfs/info.txt file). Writes are replicated to all servers, which are connected
+with write permission turned on. IO priority and permissions can be changed in run-time.
POHMELFS is capable of full data channel encryption and/or strong crypto hashing.
One can select any kernel supported cipher, encryption mode, hash type and operation mode
diff --git a/Documentation/filesystems/pohmelfs/info.txt b/Documentation/filesystems/pohmelfs/info.txt
index 4e3d50157083..db2e41393626 100644
--- a/Documentation/filesystems/pohmelfs/info.txt
+++ b/Documentation/filesystems/pohmelfs/info.txt
@@ -1,6 +1,8 @@
POHMELFS usage information.
-Mount options:
+Mount options.
+All but index, number of crypto threads and maximum IO size can changed via remount.
+
idx=%u
Each mountpoint is associated with a special index via this option.
Administrator can add or remove servers from the given index, so all mounts,
@@ -52,16 +54,27 @@ mcache_timeout=%u
Usage examples.
-Add (or remove if it already exists) server server1.net:1025 into the working set with index $idx
+Add server server1.net:1025 into the working set with index $idx
with appropriate hash algorithm and key file and cipher algorithm, mode and key file:
-$cfg -a server1.net -p 1025 -i $idx -K $hash_key -k $cipher_key
+$cfg A add -a server1.net -p 1025 -i $idx -K $hash_key -k $cipher_key
Mount filesystem with given index $idx to /mnt mountpoint.
Client will connect to all servers specified in the working set via previous command:
mount -t pohmel -o idx=$idx q /mnt
-One can add or remove servers from working set after mounting too.
+Change permissions to read-only (-I 1 option, '-I 2' - write-only, 3 - rw):
+$cfg A modify -a server1.net -p 1025 -i $idx -I 1
+
+Change IO priority to 123 (node with the highest priority gets read requests).
+$cfg A modify -a server1.net -p 1025 -i $idx -P 123
+One can check currect status of all connections in the mountstats file:
+# cat /proc/$PID/mountstats
+...
+device none mounted on /mnt with fstype pohmel
+idx addr(:port) socket_type protocol active priority permissions
+0 server1.net:1026 1 6 1 250 1
+0 server2.net:1025 1 6 1 123 3
Server installation.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index deeeed0faa8f..f49eecf2e573 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -277,8 +277,7 @@ or bottom half).
unfreeze_fs: called when VFS is unlocking a filesystem and making it writable
again.
- statfs: called when the VFS needs to get filesystem statistics. This
- is called with the kernel lock held
+ statfs: called when the VFS needs to get filesystem statistics.
remount_fs: called when the filesystem is remounted. This is called
with the kernel lock held
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index d4b05672f9f7..d76cfd8712e1 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -316,6 +316,16 @@ more details, with real examples.
#arch/m68k/fpsp040/Makefile
ldflags-y := -x
+ subdir-ccflags-y, subdir-asflags-y
+ The two flags listed above are similar to ccflags-y and as-falgs-y.
+ The difference is that the subdir- variants has effect for the kbuild
+ file where tey are present and all subdirectories.
+ Options specified using subdir-* are added to the commandline before
+ the options specified using the non-subdir variants.
+
+ Example:
+ subdir-ccflags-y := -Werror
+
CFLAGS_$@, AFLAGS_$@
CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6172e4360f60..600cdd72900c 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -134,7 +134,7 @@ and is between 256 and 4096 characters. It is defined in the file
./include/asm/setup.h as COMMAND_LINE_SIZE.
- acpi= [HW,ACPI,X86-64,i386]
+ acpi= [HW,ACPI,X86]
Advanced Configuration and Power Interface
Format: { force | off | ht | strict | noirq | rsdt }
force -- enable ACPI if default was off
@@ -218,7 +218,7 @@ and is between 256 and 4096 characters. It is defined in the file
acpi_osi="!string2" # remove built-in string2
acpi_osi= # disable all strings
- acpi_pm_good [X86-32,X86-64]
+ acpi_pm_good [X86]
Override the pmtimer bug detection: force the kernel
to assume that this machine's pmtimer latches its value
and always returns good values.
@@ -231,6 +231,35 @@ and is between 256 and 4096 characters. It is defined in the file
power state again in power transition.
1 : disable the power state check
+ acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode
+ Format: { level | edge | high | low }
+
+ acpi_serialize [HW,ACPI] force serialization of AML methods
+
+ acpi_skip_timer_override [HW,ACPI]
+ Recognize and ignore IRQ0/pin2 Interrupt Override.
+ For broken nForce2 BIOS resulting in XT-PIC timer.
+
+ acpi_sleep= [HW,ACPI] Sleep options
+ Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig,
+ old_ordering, s4_nonvs }
+ See Documentation/power/video.txt for information on
+ s3_bios and s3_mode.
+ s3_beep is for debugging; it makes the PC's speaker beep
+ as soon as the kernel's real-mode entry point is called.
+ s4_nohwsig prevents ACPI hardware signature from being
+ used during resume from hibernation.
+ old_ordering causes the ACPI 1.0 ordering of the _PTS
+ control method, with respect to putting devices into
+ low power states, to be enforced (the ACPI 2.0 ordering
+ of _PTS is used by default).
+ s4_nonvs prevents the kernel from saving/restoring the
+ ACPI NVS memory during hibernation.
+
+ acpi_use_timer_override [HW,ACPI]
+ Use timer override. For some broken Nvidia NF5 boards
+ that require a timer override, but don't have HPET
+
acpi_enforce_resources= [ACPI]
{ strict | lax | no }
Check for resource conflicts between native drivers
@@ -250,6 +279,9 @@ and is between 256 and 4096 characters. It is defined in the file
ad1848= [HW,OSS]
Format: <io>,<irq>,<dma>,<dma2>,<type>
+ add_efi_memmap [EFI; X86] Include EFI memory map in
+ kernel's map of available physical RAM.
+
advansys= [HW,SCSI]
See header of drivers/scsi/advansys.c.
@@ -459,7 +491,7 @@ and is between 256 and 4096 characters. It is defined in the file
Also note the kernel might malfunction if you disable
some critical bits.
- code_bytes [IA32/X86_64] How many bytes of object code to print
+ code_bytes [X86] How many bytes of object code to print
in an oops report.
Range: 0 - 8192
Default: 64
@@ -592,7 +624,7 @@ and is between 256 and 4096 characters. It is defined in the file
MTRR settings. This parameter disables that behavior,
possibly causing your machine to run very slowly.
- disable_timer_pin_1 [i386,x86-64]
+ disable_timer_pin_1 [X86]
Disable PIN 1 of APIC timer
Can be useful to work around chipset bugs.
@@ -624,7 +656,7 @@ and is between 256 and 4096 characters. It is defined in the file
UART at the specified I/O port or MMIO address.
The options are the same as for ttyS, above.
- earlyprintk= [X86-32,X86-64,SH,BLACKFIN]
+ earlyprintk= [X86,SH,BLACKFIN]
earlyprintk=vga
earlyprintk=serial[,ttySn[,baudrate]]
earlyprintk=dbgp
@@ -659,7 +691,7 @@ and is between 256 and 4096 characters. It is defined in the file
See Documentation/block/as-iosched.txt and
Documentation/block/deadline-iosched.txt for details.
- elfcorehdr= [IA64,PPC,SH,X86-32,X86_64]
+ elfcorehdr= [IA64,PPC,SH,X86]
Specifies physical address of start of kernel core
image elf header. Generally kexec loader will
pass this option to capture kernel.
@@ -938,7 +970,7 @@ and is between 256 and 4096 characters. It is defined in the file
See comment before marvel_specify_io7 in
arch/alpha/kernel/core_marvel.c.
- io_delay= [X86-32,X86-64] I/O delay method
+ io_delay= [X86] I/O delay method
0x80
Standard port 0x80 based delay
0xed
@@ -1000,7 +1032,7 @@ and is between 256 and 4096 characters. It is defined in the file
keepinitrd [HW,ARM]
- kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
+ kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
specifies the amount of memory usable by the kernel
for non-movable allocations. The requested amount is
spread evenly throughout all nodes in the system. The
@@ -1034,7 +1066,7 @@ and is between 256 and 4096 characters. It is defined in the file
Configure the RouterBoard 532 series on-chip
Ethernet adapter MAC address.
- kstack=N [X86-32,X86-64] Print N words from the kernel stack
+ kstack=N [X86] Print N words from the kernel stack
in oops dumps.
l2cr= [PPC]
@@ -1044,7 +1076,7 @@ and is between 256 and 4096 characters. It is defined in the file
lapic [X86-32,APIC] Enable the local APIC even if BIOS
disabled it.
- lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer
+ lapic_timer_c2_ok [X86,APIC] trust the local apic timer
in C2 power state.
libata.dma= [LIBATA] DMA control
@@ -1229,7 +1261,7 @@ and is between 256 and 4096 characters. It is defined in the file
[KNL,SH] Allow user to override the default size for
per-device physically contiguous DMA buffers.
- memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact
+ memmap=exactmap [KNL,X86] Enable setting of an exact
E820 memory map, as specified by the user.
Such memmap=exactmap lines can be constructed based on
BIOS output or other requirements. See the memmap=nn@ss
@@ -1320,7 +1352,7 @@ and is between 256 and 4096 characters. It is defined in the file
mousedev.yres= [MOUSE] Vertical screen resolution, used for devices
reporting absolute coordinates, such as tablets
- movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter
+ movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter
is similar to kernelcore except it specifies the
amount of memory used for migratable allocations.
If both kernelcore and movablecore is specified,
@@ -1422,7 +1454,7 @@ and is between 256 and 4096 characters. It is defined in the file
when a NMI is triggered.
Format: [state][,regs][,debounce][,die]
- nmi_watchdog= [KNL,BUGS=X86-32,X86-64] Debugging features for SMP kernels
+ nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels
Format: [panic,][num]
Valid num: 0,1,2
0 - turn nmi_watchdog off
@@ -1475,11 +1507,11 @@ and is between 256 and 4096 characters. It is defined in the file
nodsp [SH] Disable hardware DSP at boot time.
- noefi [X86-32,X86-64] Disable EFI runtime services support.
+ noefi [X86] Disable EFI runtime services support.
noexec [IA-64]
- noexec [X86-32,X86-64]
+ noexec [X86]
On X86-32 available only on PAE configured kernels.
noexec=on: enable non-executable mappings (default)
noexec=off: disable non-executable mappings
@@ -1525,7 +1557,7 @@ and is between 256 and 4096 characters. It is defined in the file
noirqdebug [X86-32] Disables the code which attempts to detect and
disable unhandled interrupt sources.
- no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for
+ no_timer_check [X86,APIC] Disables the code which tests for
broken timer IRQ sources.
noisapnp [ISAPNP] Disables ISA PnP code.
@@ -1689,7 +1721,7 @@ and is between 256 and 4096 characters. It is defined in the file
disable the use of PCIE advanced error reporting.
nodomains [PCI] Disable support for multiple PCI
root domains (aka PCI segments, in ACPI-speak).
- nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI
+ nommconf [X86] Disable use of MMCONFIG for PCI
Configuration
nomsi [MSI] If the PCI_MSI kernel config parameter is
enabled, this kernel boot option can be used to
@@ -1838,6 +1870,12 @@ and is between 256 and 4096 characters. It is defined in the file
autoconfiguration.
Ranges are in pairs (memory base and size).
+ ports= [IP_VS_FTP] IPVS ftp helper module
+ Default is 21.
+ Up to 8 (IP_VS_APP_MAX_PORTS) ports
+ may be specified.
+ Format: <port>,<port>....
+
print-fatal-signals=
[KNL] debug: print fatal signals
print-fatal-signals=1: print segfault info to
@@ -2380,7 +2418,7 @@ and is between 256 and 4096 characters. It is defined in the file
reported either.
unknown_nmi_panic
- [X86-32,X86-64]
+ [X86]
Set unknown_nmi_panic=1 early on boot.
usbcore.autosuspend=
@@ -2447,12 +2485,12 @@ and is between 256 and 4096 characters. It is defined in the file
medium is write-protected).
Example: quirks=0419:aaf5:rl,0421:0433:rc
- vdso= [X86-32,SH,x86-64]
+ vdso= [X86,SH]
vdso=2: enable compat VDSO (default with COMPAT_VDSO)
vdso=1: enable VDSO (default)
vdso=0: disable VDSO mapping
- vdso32= [X86-32,X86-64]
+ vdso32= [X86]
vdso32=2: enable compat VDSO (default with COMPAT_VDSO)
vdso32=1: enable 32-bit VDSO (default)
vdso32=0: disable 32-bit VDSO mapping
diff --git a/Documentation/lguest/.gitignore b/Documentation/lguest/.gitignore
new file mode 100644
index 000000000000..115587fd5f65
--- /dev/null
+++ b/Documentation/lguest/.gitignore
@@ -0,0 +1 @@
+lguest
diff --git a/Documentation/lguest/lguest.txt b/Documentation/lguest/lguest.txt
index 29510dc51510..28c747362f95 100644
--- a/Documentation/lguest/lguest.txt
+++ b/Documentation/lguest/lguest.txt
@@ -3,11 +3,11 @@
/, /` - or, A Young Coder's Illustrated Hypervisor
\\"--\\ http://lguest.ozlabs.org
-Lguest is designed to be a minimal hypervisor for the Linux kernel, for
-Linux developers and users to experiment with virtualization with the
-minimum of complexity. Nonetheless, it should have sufficient
-features to make it useful for specific tasks, and, of course, you are
-encouraged to fork and enhance it (see drivers/lguest/README).
+Lguest is designed to be a minimal 32-bit x86 hypervisor for the Linux kernel,
+for Linux developers and users to experiment with virtualization with the
+minimum of complexity. Nonetheless, it should have sufficient features to
+make it useful for specific tasks, and, of course, you are encouraged to fork
+and enhance it (see drivers/lguest/README).
Features:
@@ -37,6 +37,7 @@ Running Lguest:
"Paravirtualized guest support" = Y
"Lguest guest support" = Y
"High Memory Support" = off/4GB
+ "PAE (Physical Address Extension) Support" = N
"Alignment value to which kernel should be aligned" = 0x100000
(CONFIG_PARAVIRT=y, CONFIG_LGUEST_GUEST=y, CONFIG_HIGHMEM64G=n and
CONFIG_PHYSICAL_ALIGN=0x100000)
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 5ede7473b425..08762750f121 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -1242,7 +1242,7 @@ monitoring is enabled, and vice-versa.
To add ARP targets:
# echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target
# echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target
- NOTE: up to 10 target addresses may be specified.
+ NOTE: up to 16 target addresses may be specified.
To remove an ARP target:
# echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target
diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt
index c5948f2f9a25..88b7433d2f11 100644
--- a/Documentation/sound/alsa/HD-Audio.txt
+++ b/Documentation/sound/alsa/HD-Audio.txt
@@ -169,7 +169,7 @@ PCI SSID look-up.
What `model` option values are available depends on the codec chip.
Check your codec chip from the codec proc file (see "Codec Proc-File"
section below). It will show the vendor/product name of your codec
-chip. Then, see Documentation/sound/alsa/HD-Audio-Modelstxt file,
+chip. Then, see Documentation/sound/alsa/HD-Audio-Models.txt file,
the section of HD-audio driver. You can find a list of codecs
and `model` options belonging to each codec. For example, for Realtek
ALC262 codec chip, pass `model=ultra` for devices that are compatible
@@ -177,7 +177,7 @@ with Samsung Q1 Ultra.
Thus, the first thing you can do for any brand-new, unsupported and
non-working HD-audio hardware is to check HD-audio codec and several
-different `model` option values. If you have a luck, some of them
+different `model` option values. If you have any luck, some of them
might suit with your device well.
Some codecs such as ALC880 have a special model option `model=test`.
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index 0f5122eb282b..4a02d2508bc8 100644
--- a/Documentation/spi/spi-summary
+++ b/Documentation/spi/spi-summary
@@ -511,10 +511,16 @@ SPI MASTER METHODS
This sets up the device clock rate, SPI mode, and word sizes.
Drivers may change the defaults provided by board_info, and then
call spi_setup(spi) to invoke this routine. It may sleep.
+
Unless each SPI slave has its own configuration registers, don't
change them right away ... otherwise drivers could corrupt I/O
that's in progress for other SPI devices.
+ ** BUG ALERT: for some reason the first version of
+ ** many spi_master drivers seems to get this wrong.
+ ** When you code setup(), ASSUME that the controller
+ ** is actively processing transfers for another device.
+
master->transfer(struct spi_device *spi, struct spi_message *message)
This must not sleep. Its responsibility is arrange that the
transfer happens and its complete() callback is issued. The two
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-13 08:52:49 +0000