Merge http://linus.bkbits.net/linux-2.5

into maxwell.earthlink.net:/tmp/linus-2.5

4 files changed, 417 insertions, 26 deletions

diff --git a/Documentation/cli-sti-removal.txt b/Documentation/cli-sti-removal.txt
new file mode 100644
index 000000000000..8192ffefc711
--- /dev/null
+++ b/Documentation/cli-sti-removal.txt
@@ -0,0 +1,115 @@
+
+#### cli()/sti() removal guide, started by Ingo Molnar <mingo@redhat.com>
+
+
+as of 2.5.28, four popular macros have been removed on SMP, and
+are being phased out on UP:
+
+ cli(), sti(), save_flags(flags), restore_flags(flags)
+
+until now it was possible to protect driver code against interrupt
+handlers via a cli(), but from now on other, more lightweight methods
+have to be used for synchronization, such as spinlocks or semaphores.
+
+for example, driver code that used to do something like:
+
+	struct driver_data;
+
+	irq_handler (...)
+	{
+		....
+		driver_data.finish = 1;
+		driver_data.new_work = 0;
+		....
+	}
+
+	...
+
+	ioctl_func (...)
+	{
+		...
+		cli();
+		...
+		driver_data.finish = 0;
+		driver_data.new_work = 2;
+		...
+		sti();
+		...
+	}
+
+was SMP-correct because the cli() function ensured that no
+interrupt handler (amongst them the above irq_handler()) function
+would execute while the cli()-ed section is executing.
+
+but from now on a more direct method of locking has to be used:
+
+	spinlock_t driver_lock = SPIN_LOCK_UNLOCKED;
+	struct driver_data;
+
+	irq_handler (...)
+	{
+		unsigned long flags;
+		....
+		spin_lock_irqsave(&driver_lock, flags);
+		....
+		driver_data.finish = 1;
+		driver_data.new_work = 0;
+		....
+		spin_unlock_irqrestore(&driver_lock, flags);
+		....
+	}
+
+	...
+
+	ioctl_func (...)
+	{
+		...
+		spin_lock_irq(&driver_lock);
+		...
+		driver_data.finish = 0;
+		driver_data.new_work = 2;
+		...
+		spin_unlock_irq(&driver_lock);
+		...
+	}
+
+the above code has a number of advantages:
+
+- the locking relation is easier to understand - actual lock usage
+  pinpoints the critical sections. cli() usage is too opaque.
+  Easier to understand means it's easier to debug.
+
+- it's faster, because spinlocks are faster to acquire than the
+  potentially heavily-used IRQ lock. Furthermore, your driver does
+  not have to wait eg. for a big heavy SCSI interrupt to finish,
+  because the driver_lock spinlock is only used by your driver.
+  cli() on the other hand was used by many drivers, and extended
+  the critical section to the whole IRQ handler function - creating
+  serious lock contention.
+ 
+
+to make the transition easier, we've still kept the cli(), sti(),
+save_flags() and restore_flags() macros defined on UP systems - but
+their usage will be phased out until the 2.6 kernel is released.
+
+drivers that want to disable local interrupts (interrupts on the
+current CPU), can use the following four macros:
+
+  __cli(), __sti(), __save_flags(flags), __restore_flags(flags)
+
+but beware, their meaning and semantics are much simpler, far from
+that of cli(), sti(), save_flags(flags) and restore_flags(flags).
+
+
+another related change is that synchronize_irq() now takes a parameter:
+synchronize_irq(irq). This change too has the purpose of making SMP
+synchronization more lightweight - this way you can wait for your own
+interrupt handler to finish, no need to wait for other IRQ sources.
+
+
+why were these changes done? The main reason was the architectural burden
+of maintaining the cli()/sti() interface - it became a real problem. The
+new interrupt system is much more streamlined, easier to understand, debug,
+and it's also a bit faster - the same happened to it that will happen to
+cli()/sti() using drivers once they convert to spinlocks :-)
+
diff --git a/Documentation/preempt-locking.txt b/Documentation/preempt-locking.txt
index a9eac1c15718..580814915c70 100644
--- a/Documentation/preempt-locking.txt
+++ b/Documentation/preempt-locking.txt
@@ -70,7 +70,8 @@ duration of the critical region.
 preempt_enable()		decrement the preempt counter
 preempt_disable()		increment the preempt counter
 preempt_enable_no_resched()	decrement, but do not immediately preempt
-preempt_get_count()		return the preempt counter
+preempt_check_resched()		if needed, reschedule
+preempt_count()			return the preempt counter
 
 The functions are nestable.  In other words, you can call preempt_disable
 n-times in a code path, and preemption will not be reenabled until the n-th
diff --git a/Documentation/serial/driver b/Documentation/serial/driver
new file mode 100644
index 000000000000..7396d0727927
--- /dev/null
+++ b/Documentation/serial/driver
@@ -0,0 +1,300 @@
+
+			Low Level Serial API
+			--------------------
+
+
+   $Id: driver,v 1.9 2002/07/06 16:51:43 rmk Exp $
+
+
+This document is meant as a brief overview of some aspects of the new serial
+driver.  It is not complete, any questions you have should be directed to
+<rmk@arm.linux.org.uk>
+
+The reference implementation is contained within serial_amba.c.
+
+
+
+Low Level Serial Hardware Driver
+--------------------------------
+
+The low level serial hardware driver is responsible for supplying port
+information (defined by uart_port) and a set of control methods (defined
+by uart_ops) to the core serial driver.  The low level driver is also
+responsible for handling interrupts for the port, and providing any
+console support.
+
+
+Console Support
+---------------
+
+The serial core provides a few helper functions.  This includes identifing
+the correct port structure (via uart_get_console) and decoding command line
+arguments (uart_parse_options).
+
+
+Locking
+-------
+
+It is the responsibility of the low level hardware driver to perform the
+necessary locking using port->lock.  There are some exceptions (which
+are described in the uart_ops listing below.)
+
+There are three locks.  A per-port spinlock, a per-port tmpbuf semaphore,
+and an overall semaphore.
+
+From the core driver perspective, the port->lock locks the following
+data:
+
+	port->mctrl
+	port->icount
+	info->xmit.head (circ->head)
+	info->xmit.tail (circ->tail)
+
+The low level driver is free to use this lock to provide any additional
+locking.
+
+The core driver uses the info->tmpbuf_sem lock to prevent multi-threaded
+access to the info->tmpbuf bouncebuffer used for port writes.
+
+The port_sem semaphore is used to protect against ports being added/
+removed or reconfigured at inappropriate times.
+
+
+uart_ops
+--------
+
+The uart_ops structure is the main interface between serial_core and the
+hardware specific driver.  It contains all the methods to control the
+hardware.
+
+  tx_empty(port)
+	This function tests whether the transmitter fifo and shifter
+	for the port described by 'port' is empty.  If it is empty,
+	this function should return TIOCSER_TEMT, otherwise return 0.
+	If the port does not support this operation, then it should
+	return TIOCSER_TEMT.
+
+	Locking: none.
+	Interrupts: caller dependent.
+	This call must not sleep
+
+  set_mctrl(port, mctrl)
+	This function sets the modem control lines for port described
+	by 'port' to the state described by mctrl.  The relevant bits
+	of mctrl are:
+		- TIOCM_RTS	RTS signal.
+		- TIOCM_DTR	DTR signal.
+		- TIOCM_OUT1	OUT1 signal.
+		- TIOCM_OUT2	OUT2 signal.
+	If the appropriate bit is set, the signal should be driven
+	active.  If the bit is clear, the signal should be driven
+	inactive.
+
+	Locking: port->lock taken.
+	Interrupts: locally disabled.
+	This call must not sleep
+
+  get_mctrl(port)
+	Returns the current state of modem control inputs.  The state
+	of the outputs should not be returned, since the core keeps
+	track of their state.  The state information should include:
+		- TIOCM_DCD	state of DCD signal
+		- TIOCM_CTS	state of CTS signal
+		- TIOCM_DSR	state of DSR signal
+		- TIOCM_RI	state of RI signal
+	The bit is set if the signal is currently driven active.  If
+	the port does not support CTS, DCD or DSR, the driver should
+	indicate that the signal is permanently active.  If RI is
+	not available, the signal should not be indicated as active.
+
+	Locking: none.
+	Interrupts: caller dependent.
+	This call must not sleep
+
+  stop_tx(port,tty_stop)
+	Stop transmitting characters.  This might be due to the CTS
+	line becoming inactive or the tty layer indicating we want
+	to stop transmission.
+
+	tty_stop: 1 if this call is due to the TTY layer issuing a
+	          TTY stop to the driver (equiv to rs_stop).
+
+	Locking: none.
+	Interrupts: caller dependent.
+	This call must not sleep
+
+  start_tx(port,tty_start)
+	start transmitting characters.  (incidentally, nonempty will
+	always be nonzero, and shouldn't be used - it will be dropped).
+
+	tty_start: 1 if this call was due to the TTY layer issuing
+	           a TTY start to the driver (equiv to rs_start)
+
+	Locking: port->lock taken.
+	Interrupts: locally disabled.
+	This call must not sleep
+
+  stop_rx(port)
+	Stop receiving characters; the port is in the process of
+	being closed.
+
+	Locking: none.
+	Interrupts: caller dependent.
+	This call must not sleep
+
+  enable_ms(port)
+	Enable the modem status interrupts.
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  break_ctl(port,ctl)
+	Control the transmission of a break signal.  If ctl is
+	nonzero, the break signal should be transmitted.  The signal
+	should be terminated when another call is made with a zero
+	ctl.
+
+	Locking: none.
+	Interrupts: caller dependent.
+	This call must not sleep
+
+  startup(port)
+	Grab any interrupt resources and initialise any low level driver
+	state.  Enable the port for reception.  It should not activate
+	RTS nor DTR; this will be done via a separate call to set_mctrl.
+
+	Locking: port_sem taken.
+	Interrupts: globally disabled.
+
+  shutdown(port)
+	Disable the port, disable any break condition that may be in
+	effect, and free any interrupt resources.  It should not disable
+	RTS nor DTR; this will have already been done via a separate
+	call to set_mctrl.
+
+	Locking: port_sem taken.
+	Interrupts: caller dependent.
+
+  change_speed(port,cflag,iflag,quot)
+	Change the port parameters, including word length, parity, stop
+	bits.  Update read_status_mask and ignore_status_mask to indicate
+	the types of events we are interested in receiving.  Relevant
+	cflag bits are:
+		CSIZE	- word size
+		CSTOPB	- 2 stop bits
+		PARENB	- parity enable
+		PARODD	- odd parity (when PARENB is in force)
+		CREAD	- enable reception of characters (if not set,
+			  still receive characters from the port, but
+			  throw them away.
+		CRTSCTS	- if set, enable CTS status change reporting
+		CLOCAL	- if not set, enable modem status change
+			  reporting.
+	Relevant iflag bits are:
+		INPCK	- enable frame and parity error events to be
+			  passed to the TTY layer.
+		BRKINT
+		PARMRK	- both of these enable break events to be
+			  passed to the TTY layer.
+
+		IGNPAR	- ignore parity and framing errors
+		IGNBRK	- ignore break errors,  If IGNPAR is also
+			  set, ignore overrun errors as well.
+	The interaction of the iflag bits is as follows (parity error
+	given as an example):
+	Parity error	INPCK	IGNPAR
+	None		n/a	n/a	character received
+	Yes		n/a	0	character discarded
+	Yes		0	1	character received, marked as
+					TTY_NORMAL
+	Yes		1	1	character received, marked as
+					TTY_PARITY
+
+	Locking: none.
+	Interrupts: caller dependent.
+	This call must not sleep
+
+  pm(port,state,oldstate)
+	perform any power management related activities on the specified
+	port.  state indicates the new state (defined by ACPI D0-D3),
+	oldstate indicates the previous state.  Essentially, D0 means
+	fully on, D3 means powered down.
+
+	This function should not be used to grab any resources.
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  type(port)
+	Return a pointer to a string constant describing the specified
+	port, or return NULL, in which case the string 'unknown' is
+	substituted.
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  release_port(port)
+	Release any memory and IO region resources currently in use by
+	the port.
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  request_port(port)
+	Request any memory and IO region resources required by the port.
+	If any fail, no resources should be registered when this function
+	returns, and it should return -EBUSY on failure.
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  config_port(port,type)
+	Perform any autoconfiguration steps required for the port.  `type`
+	contains a bit mask of the required configuration.  UART_CONFIG_TYPE
+	indicates that the port requires detection and identification.
+	port->type should be set to the type found, or PORT_UNKNOWN if
+	no port was detected.
+
+	UART_CONFIG_IRQ indicates autoconfiguration of the interrupt signal,
+	which should be probed using standard kernel autoprobing techniques.
+	This is not necessary on platforms where ports have interrupts
+	internally hard wired (eg, system on a chip implementations).
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  verify_port(port,serinfo)
+	Verify the new serial port information contained within serinfo is
+	suitable for this port type.
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+  ioctl(port,cmd,arg)
+	Perform any port specific IOCTLs.  IOCTL commands must be defined
+	using the standard numbering system found in <asm/ioctl.h>
+
+	Locking: none.
+	Interrupts: caller dependent.
+
+
+Other notes
+-----------
+
+It is intended some day to drop the 'unused' entries from uart_port, and
+allow low level drivers to register their own individual uart_port's with
+the core.  This will allow drivers to use uart_port as a pointer to a
+structure containing both the uart_port entry with their own extensions,
+thus:
+
+	struct my_port {
+		struct uart_port	port;
+		int			my_stuff;
+	};
+
+Todo
+----
+
+Please see the BUGS file in CVS at
+
+	http://cvs.arm.linux.org.uk/cgi/viewcvs.cgi/serial/BUGS
diff --git a/Documentation/usb/ov511.txt b/Documentation/usb/ov511.txt
index f7a2108e7530..4c33f949dfb0 100644
--- a/Documentation/usb/ov511.txt
+++ b/Documentation/usb/ov511.txt
@@ -128,16 +128,6 @@ MODULE PARAMETERS:
         programs that expect RGB data (e.g. gqcam) to work with this driver. If
         your colors look VERY wrong, you may want to change this.
 
-  NAME: buf_timeout (Temporarily disabled. Memory is deallocated immediately)
-  TYPE: integer
-  DEFAULT: 5 (seconds)
-  DESC: Number of seconds before unused frame buffers are deallocated.
-        Previously, memory was allocated upon open() and deallocated upon
-        close(). Deallocation now occurs only if the driver is closed and this
-        timeout is reached. If you are capturing frames less frequently than
-        the default timeout, increase this. This will not make any difference
-        with programs that capture multiple frames during an open/close cycle.
-
   NAME: cams
   TYPE: integer (1-4 for OV511, 1-31 for OV511+)
   DEFAULT: 1
@@ -161,13 +151,6 @@ MODULE PARAMETERS:
   DESC: This configures the camera's sensor to transmit a colored test-pattern
         instead of an image. This does not work correctly yet.
 
-  NAME: sensor_gbr (*** TEMPORARILY DISABLED ***)
-  TYPE: integer (Boolean)
-  DEFAULT: 0
-  DESC: This makes the sensor output GBR422 instead of YUV420. This saves the
-        driver the trouble of converting YUV to RGB, but it currently does not
-        work very well (the colors are not quite right)
-
   NAME: dumppix
   TYPE: integer (0-2)
   DEFAULT: 0
@@ -259,14 +242,6 @@ MODULE PARAMETERS:
 		13  VIDEO_PALETTE_YUV422P   (YUV 4:2:2 Planar)
 		15  VIDEO_PALETTE_YUV420P   (YUV 4:2:0 Planar, same as 10)
 
-  NAME: tuner
-  TYPE: integer
-  DEFAULT: -1 (autodetect)
-  DESC: This sets the exact type of the tuner module in a device. This is set
-	automatically based on the custom ID of the OV511 device. In cases
-	where this fails, you can override this auto-detection. Please see
-	linux/drivers/media/video/tuner.h for a complete list.
-
   NAME: backlight
   TYPE: integer (Boolean)
   DEFAULT: 0 (off)