All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization. So make those functions acquire then release the BKL to be
on the safe side.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
This documents the fact that somebody looked at the relevant open()
functions and concluded that, due to their trivial nature, no locking was
needed.
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The AMD CS5535/CS5536 GPIO has two alternate output modes: AUX-1 and AUX-2.
When either AUX is enabled, the cs5535_gpio driver cannot control the
output.
Some BIOS code for the Geode processor enables AUX-1 for GPIO-1, which
configures it as the PC BEEP output.
This patch will disable AUX-1 and AUX-2 when the user enables output.
Signed-of-by: Ben Gardner <gardner.ben@gmail.com>
Cc: Richard Knutsson <ricknu-0@student.ltu.se>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark the static struct file_operations in drivers/char as const. Making
them const prevents accidental bugs, and moves them to the .rodata section
so that they no longer do any false sharing; in addition with the proper
debug option they are then protected against corruption..
[akpm@osdl.org: build fix]
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
During module unloading, cdev_del() must be called to unmap cdev related
kobject references and other cleanups(such as inode->i_cdev being set to
NULL) which prevents the OOPS upon subsequent loading, usage and unloading
of modules(as seen in the mail thread
http://marc.theaimsgroup.com/?l=linux-kernel&m=114533640609018&w=2).
Also, remove unneeded test of gpio_base.
Signed-off-by: Thayumanavar Sachithanantham <thayumk@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A simple driver for the CS5535 and CS5536 that allows a user-space program
to manipulate GPIO pins. The CS5535/CS5536 chips are Geode processor
companion devices.
Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Richard Knutsson <ricknu-0@student.ltu.se>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
