---

yaml
---
r: 19695
b: refs/heads/master
c: 42c5e15
h: refs/heads/master
i:
  19693: 782cadf
  19691: 6ab5e3f
  19687: 4220aeb
  19679: ef2c509
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d540c7428d297ab041e6cac72b9045e7b8f93f2b
+refs/heads/master: 42c5e15f18d63c1ecf79d52bdaf4ea31cd22416d

trunk/Documentation/driver-model/overview.txt

@@ -1,43 +1,50 @@
 The Linux Kernel Device Model
 
-Patrick Mochel	<mochel@digitalimplant.org>
+Patrick Mochel	<mochel@osdl.org>
 
-Drafted 26 August 2002
-Updated 31 January 2006
+26 August 2002
 
 
 Overview
 ~~~~~~~~
 
-The Linux Kernel Driver Model is a unification of all the disparate driver
-models that were previously used in the kernel. It is intended to augment the
+This driver model is a unification of all the current, disparate driver models
+that are currently in the kernel. It is intended to augment the
 bus-specific drivers for bridges and devices by consolidating a set of data
 and operations into globally accessible data structures.
 
-Traditional driver models implemented some sort of tree-like structure
-(sometimes just a list) for the devices they control. There wasn't any
-uniformity across the different bus types.
+Current driver models implement some sort of tree-like structure (sometimes
+just a list) for the devices they control. But, there is no linkage between
+the different bus types.
 
-The current driver model provides a comon, uniform data model for describing
-a bus and the devices that can appear under the bus. The unified bus
-model includes a set of common attributes which all busses carry, and a set
-of common callbacks, such as device discovery during bus probing, bus
-shutdown, bus power management, etc.
+A common data structure can provide this linkage with little overhead: when a
+bus driver discovers a particular device, it can insert it into the global
+tree as well as its local tree. In fact, the local tree becomes just a subset
+of the global tree.
+
+Common data fields can also be moved out of the local bus models into the
+global model. Some of the manipulations of these fields can also be
+consolidated. Most likely, manipulation functions will become a set
+of helper functions, which the bus drivers wrap around to include any
+bus-specific items.
+
+The common device and bridge interface currently reflects the goals of the
+modern PC: namely the ability to do seamless Plug and Play, power management,
+and hot plug. (The model dictated by Intel and Microsoft (read: ACPI) ensures
+us that any device in the system may fit any of these criteria.)
+
+In reality, not every bus will be able to support such operations. But, most
+buses will support a majority of those operations, and all future buses will.
+In other words, a bus that doesn't support an operation is the exception,
+instead of the other way around.
 
-The common device and bridge interface reflects the goals of the modern
-computer: namely the ability to do seamless device "plug and play", power
-management, and hot plug. In particular, the model dictated by Intel and
-Microsoft (namely ACPI) ensures that almost every device on almost any bus
-on an x86-compatible system can work within this paradigm.  Of course,
-not every bus is able to support all such operations, although most
-buses support a most of those operations.
 
 
 Downstream Access
 ~~~~~~~~~~~~~~~~~
 
 Common data fields have been moved out of individual bus layers into a common
-data structure. These fields must still be accessed by the bus layers,
+data structure. But, these fields must still be accessed by the bus layers,
 and sometimes by the device-specific drivers.
 
 Other bus layers are encouraged to do what has been done for the PCI layer.
@@ -46,7 +53,7 @@ struct pci_dev now looks like this:
 struct pci_dev {
 	...
 
-	struct device dev;
+	struct device device;
 };
 
 Note first that it is statically allocated. This means only one allocation on
@@ -57,9 +64,9 @@ the two.
 
 The PCI bus layer freely accesses the fields of struct device. It knows about
 the structure of struct pci_dev, and it should know the structure of struct
-device. Individual PCI device drivers that have been converted the the current
-driver model generally do not and should not touch the fields of struct device,
-unless there is a strong compelling reason to do so.
+device. PCI devices that have been converted generally do not touch the fields
+of struct device. More precisely, device-specific drivers should not touch
+fields of struct device unless there is a strong compelling reason to do so.
 
 This abstraction is prevention of unnecessary pain during transitional phases.
 If the name of the field changes or is removed, then every downstream driver

trunk/Documentation/parport-lowlevel.txt

@@ -1068,7 +1068,7 @@ SYNOPSIS
 
 struct parport_operations {
 	...
-	void (*write_control) (struct parport *port, unsigned char s);
+	void (*write_status) (struct parport *port, unsigned char s);
 	...
 };
 
@@ -1097,9 +1097,9 @@ SYNOPSIS
 
 struct parport_operations {
 	...
-	unsigned char (*frob_control) (struct parport *port,
-				       unsigned char mask,
-				       unsigned char val);
+	void (*frob_control) (struct parport *port,
+	                      unsigned char mask,
+			      unsigned char val);
 	...
 };