Update documentation for the hw_random support to be current:
- Documentation/hw_random.txt has been updated to reflect the
current code: it's a framework now, a "core" with a small
sysfs interface, that hardware-specific drivers plug in to.
Text specific to Intel hardware is now at the end.
- Kconfig now references the Documentation/hw_random.txt file
and better explains what this really does.
Both chunks of documentation now higlight the fact that the kernel entropy
pool is maintained by "rngd", and this driver has nothing directly to do with
that important task.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
unsigned long != __le32, TYVM, and unsigned char[4] is not guaranteed
to be aligned for u32.
While we are at it, sanitize sOutDW() a bit - have it take Byte_t * and
handle dereferencing internally.
NB: sWriteTxPrioByte() is almost certainly buggered on big-endian and is
missing cpu_to_le16() on assignments to *WordPtr; I've left it alone for now.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes a problem on 64-bit with 4GB with ATI RS690 chipsets. It
makes sure the pcigart table is allocated in coherent memory for DMA operations.
Signed-off-by: Dave Airlie <airlied@redhat.com>
It's worth remembering that all new bright ideas on how to make this command reader work properly and according to docs will probably fail :( Bring in some old code.
Also allow a larger SG-DMA download stride, and remove unnecessary waits for
command regulators pauses.
Signed-off-by: Dave Airlie <airlied@redhat.com>
The i915_vblank_swap() function schedules an automatic buffer swap
upon receipt of the vertical sync interrupt. Such an operation is
lengthy so it can't be allowed to happen in normal interrupt context,
thus the DRM implements this by scheduling the work in a kernel
softirq-scheduled tasklet. In order for the buffer swap to work
safely, the DRM's central lock must be taken, via a call to
drm_lock_take() located in drivers/char/drm/drm_irq.c within the
function drm_locked_tasklet_func(). The lock-taking logic uses a
non-interrupt-blocking spinlock to implement the manipulations needed
to take the lock. This semantic would be safe if all attempts to use
the spinlock only happen from process context. However this buffer
swap happens from softirq context which is really a form of interrupt
context. Thus we have an unsafe situation, in that
drm_locked_tasklet_func() can block on a spinlock already taken by a
thread in process context which will never get scheduled again because
of the blocked softirq tasklet. This wedges the kernel hard.
To trigger this bug, run a dual-head cloned mode configuration which
uses the i915 drm, then execute an opengl application which
synchronizes buffer swaps against the vertical sync interrupt. In my
testing, a lockup always results after running anywhere from 5 minutes
to an hour and a half. I believe dual-head is needed to really
trigger the problem because then the vertical sync interrupt handling
is no longer predictable (due to being interrupt-sourced from two
different heads running at different speeds). This raises the
probability of the tasklet trying to run while the userspace DRI is
doing things to the GPU (and manipulating the DRM lock).
The fix is to change the relevant spinlock semantics to be the
interrupt-blocking form. After this change I am no longer able to
trigger the lockup; the longest test run so far was 20 hours (test
stopped after that point).
Note: I have examined the places where this spinlock is being
employed; all are reasonably short bounded sequences and should be
suitable for interrupts being blocked without impacting overall kernel
interrupt response latency.
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
drivers: fix dma_get_required_mask
firmware: provide stubs for the FW_LOADER=n case
nozomi: fix initialization and early flow control access
sysdev: fix problem with sysdev_class being re-registered
Due to some flaws in the initialization and flow control
code kernel oopses could be triggered e.g. when accessing
the card too early after insertion.
See e.g. kernel.org bug #10077.
The main part of the fix is a trivial state management
making sure the card is realy ready to use before allowing
any access.
Signed-off-by: Frank Seidel <fseidel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This has been around for a while but nobody reported it until recently.
Resubmitting the fix as it's appropriate for 2.6.25
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
randconfig testing found a bootup lockup in drivers/char/esp.c because
of a spinlock that wasn't correctly initialized.
I'm not sure why it became more prominent in 2.6.25-rc4, the bug seems
rather old and i've been doing allyesconfig bootups for ages with
CONFIG_ESP enabled.
This fixes this bootup lockup:
PM: Adding info for No Bus:ttyP63
ttyP32 at 0x0240 (irq = 0) is an ESP primary port
BUG: spinlock lockup on CPU#0, swapper/1, f56dd004
Pid: 1, comm: swapper Not tainted 2.6.25-rc4-sched-devel.git-x86-latest.git #402 [<c03ac6f4>] _raw_spin_lock+0x134/0x140
[<c08649be>] _spin_lock_irqsave+0x5e/0x80
[<c0b9fbfe>] ? espserial_init+0x2be/0x6e0
[<c0b9fbfe>] espserial_init+0x2be/0x6e0
[<c0b877a3>] kernel_init+0x83/0x260
[<c0b9f940>] ? espserial_init+0x0/0x6e0
[<c010416a>] ? restore_nocheck_notrace+0x0/0xe
[<c0b87720>] ? kernel_init+0x0/0x260
[<c0b87720>] ? kernel_init+0x0/0x260
[<c0104507>] kernel_thread_helper+0x7/0x10
=======================
kzalloc() is not the way to initialize spinlocks anymore.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit e6bafba5b4 ("wmi: (!x & y)
strikes again"), a bug was fixed that involved converting !x & y to !(x
& y). The code below shows the same pattern, and thus should perhaps be
fixed in the same way.
This is not tested and clearly changes the semantics, so it is only
something to consider.
The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@ expression E1,E2; @@
(
!E1 & !E2
|
- !E1 & E2
+ !(E1 & E2)
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
VT notifier callbacks need to be aware of console switches. This is already
partially done from console_callback(), but at that time fg_console, cursor
positions, etc. are not yet updated and hence screen readers fetch the old
values.
This adds an update notify after all of the values are updated in
redraw_screen(vc, 1).
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oddly enough, unsigned int c = '\300'; puts a "negative" value in c, not
0300... This fixes the default unicode compose table by using integers
instead of character constants.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix hpet_(un)register_irq_handler() for when CONFIG_HPET_EMULATE_RTC=n. They
are provided macros that substitute value 0, but if they are called as
functions and the return value isn't checked, the following warnings appear:
drivers/char/rtc.c: In function `rtc_init':
drivers/char/rtc.c:1063: warning: statement with no effect
drivers/char/rtc.c: In function `rtc_exit':
drivers/char/rtc.c:1157: warning: statement with no effect
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes various items pointed out during a review of the hwicap driver.
Primarily, reversed memcpy calls, re-entrancy issues, and mutex conversion
have been addressed. There are also fixes to comments to use the kerneldoc
format, as well as some sparse annotations.
Signed-off-by: Stephen Neuendorffer <stephen.neuendorffer@xilinx.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Make sure the restoration correctly restores the AR registers by
flipping the ARX register into index mode before doing anything.
Without this, some people have had the text mode restore all green.
Signed-off-by: Jesse Barnes <jesse.barnes@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
agp: fix missing casts that produced a warning.
agp: add support for 662/671 to agp driver
fix historic ioremap() abuse in AGP
agp/sis: Suspend support for SiS AGP
agp/sis: Clear bit 2 from aperture size byte as well
David Brownell
Al Viro
Dave Airlie
Alex Deucher
Thomas Hellstrom
Mike Isely
Jiri Slaby
Linus Torvalds
Frank Seidel
Alan Cox
Ingo Molnar
Julia Lawall
David Sterba
Samuel Thibault
Harvey Harrison
Paul Mackerras
David Howells
Stephen Neuendorffer
Jesse Barnes
Chaoyu Chen