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Revision 810198bc9c109489dfadc57131c5183ce6ad2d7d authored by Rajashekhara, Sudhakar on 12 July 2011, 10:28:53 UTC, committed by Sekhar Nori on 07 September 2011, 08:53:01 UTC 
ARM: davinci: da850 EVM: read mac address from SPI flash
 
DA850/OMAP-L138 EMAC driver uses random mac address instead of
a fixed one because the mac address is not stuffed into EMAC
platform data.

This patch provides a function which reads the mac address
stored in SPI flash (registered as MTD device) and populates the
EMAC platform data. The function which reads the mac address is
registered as a callback which gets called upon addition of MTD
device.

NOTE: In case the MAC address stored in SPI flash is erased, follow
the instructions at [1] to restore it.

[1] http://processors.wiki.ti.com/index.php/GSG:_OMAP-L138_DVEVM_Additional_Procedures#Restoring_MAC_address_on_SPI_Flash

Modifications in v2:
Guarded registering the mtd_notifier only when MTD is enabled.
Earlier this was handled using mtd_has_partitions() call, but
this has been removed in Linux v3.0.

Modifications in v3:
a. Guarded da850_evm_m25p80_notify_add() function and
   da850evm_spi_notifier structure with CONFIG_MTD macros.
b. Renamed da850_evm_register_mtd_user() function to
   da850_evm_setup_mac_addr() and removed the struct mtd_notifier
   argument to this function.
c. Passed the da850evm_spi_notifier structure to register_mtd_user()
   function.

Modifications in v4:
Moved the da850_evm_setup_mac_addr() function within the first
CONFIG_MTD ifdef construct.

Signed-off-by: Rajashekhara, Sudhakar <sudhakar.raj@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Cc: stable@kernel.org
1 parent ddf2835
Raw File
dnotify.txt 
		Linux Directory Notification
		============================

	   Stephen Rothwell <sfr@canb.auug.org.au>

The intention of directory notification is to allow user applications
to be notified when a directory, or any of the files in it, are changed.
The basic mechanism involves the application registering for notification
on a directory using a fcntl(2) call and the notifications themselves
being delivered using signals.

The application decides which "events" it wants to be notified about.
The currently defined events are:

	DN_ACCESS	A file in the directory was accessed (read)
	DN_MODIFY	A file in the directory was modified (write,truncate)
	DN_CREATE	A file was created in the directory
	DN_DELETE	A file was unlinked from directory
	DN_RENAME	A file in the directory was renamed
	DN_ATTRIB	A file in the directory had its attributes
			changed (chmod,chown)

Usually, the application must reregister after each notification, but
if DN_MULTISHOT is or'ed with the event mask, then the registration will
remain until explicitly removed (by registering for no events).

By default, SIGIO will be delivered to the process and no other useful
information.  However, if the F_SETSIG fcntl(2) call is used to let the
kernel know which signal to deliver, a siginfo structure will be passed to
the signal handler and the si_fd member of that structure will contain the
file descriptor associated with the directory in which the event occurred.

Preferably the application will choose one of the real time signals
(SIGRTMIN + <n>) so that the notifications may be queued.  This is
especially important if DN_MULTISHOT is specified.  Note that SIGRTMIN
is often blocked, so it is better to use (at least) SIGRTMIN + 1.

Implementation expectations (features and bugs :-))
---------------------------

The notification should work for any local access to files even if the
actual file system is on a remote server.  This implies that remote
access to files served by local user mode servers should be notified.
Also, remote accesses to files served by a local kernel NFS server should
be notified.

In order to make the impact on the file system code as small as possible,
the problem of hard links to files has been ignored.  So if a file (x)
exists in two directories (a and b) then a change to the file using the
name "a/x" should be notified to a program expecting notifications on
directory "a", but will not be notified to one expecting notifications on
directory "b".

Also, files that are unlinked, will still cause notifications in the
last directory that they were linked to.

Configuration
-------------

Dnotify is controlled via the CONFIG_DNOTIFY configuration option.  When
disabled, fcntl(fd, F_NOTIFY, ...) will return -EINVAL.

Example
-------
See Documentation/filesystems/dnotify_test.c for an example.

NOTE
----
Beginning with Linux 2.6.13, dnotify has been replaced by inotify.
See Documentation/filesystems/inotify.txt for more information on it.
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