linux-toradex.git/drivers/block/DAC960.c, branch v2.6.19.2

Various drivers' irq handlers: kill dead code, needless casts

2006-10-06T19:00:58+00:00

- Eliminate casts to/from void*

- Eliminate checks for conditions that never occur.  These typically
  fall into two classes:

	1) Checking for 'dev_id == NULL', then it is never called with
	NULL as an argument.

	2) Checking for invalid irq number, when the only caller (the
	system) guarantees the irq handler is called with the proper
	'irq' number argument.

Signed-off-by: Jeff Garzik

IRQ: Maintain regs pointer globally rather than passing to IRQ handlers

2006-10-05T14:10:12+00:00

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells 
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

[PATCH] completions: lockdep annotate on stack completions

2006-10-01T07:39:24+00:00

All on stack DECLARE_COMPLETIONs should be replaced by:
DECLARE_COMPLETION_ONSTACK

Signed-off-by: Peter Zijlstra 
Acked-by: Ingo Molnar 
Acked-by: Benjamin Herrenschmidt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Remove ->waiting member from struct request

2006-09-30T18:29:12+00:00

As the comments indicates in blkdev.h, we can fold it into ->end_io_data
usage as that is really what ->waiting is. Fixup the users of
blk_end_sync_rq().

Signed-off-by: Jens Axboe

[SCSI] DAC960: PCI id table fixup

2006-08-04T13:29:17+00:00

The PCI ID table in the DAC960 driver conflicts with some devices
that use the ipr driver. All ipr adapters that use this chip
have an IBM subvendor ID and all DAC960 adapters that use this
chip have a Mylex subvendor id.

Signed-off-by: Brian King 
Signed-off-by: James Bottomley

[PATCH] irq-flags: drivers/block Use the new IRQF_ constants

2006-07-02T20:58:49+00:00

Signed-off-by: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: Benjamin Herrenschmidt 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] devfs: Remove the gendisk devfs_name field as it's no longer needed

2006-06-26T19:25:08+00:00

And remove the now unneeded number field.
Also fixes all drivers that set these fields.

Signed-off-by: Greg Kroah-Hartman

[SCSI] fix (unlikely) memory leak in DAC960 driver

2006-05-20T14:23:23+00:00

The Coverity checker found a memory leak (bug nr. 1245) in
 drivers/block/DAC960.c::DAC960_V2_ProcessCompletedCommand()

The leak is pretty unlikely since it requires that the first of two
successive kmalloc() calls fail while the second one succeeds. But it can
still happen even if it's unlikely.

If the first call that allocates 'PhysicalDeviceInfo' fails but the one
that allocates 'InquiryUnitSerialNumber' succeeds, then we will leak the
memory allocated to 'InquiryUnitSerialNumber' when the variable goes out
of scope.

A simple fix for this is to change the existing code that frees
'PhysicalDeviceInfo' if that one was allocated but
'InquiryUnitSerialNumber' was not, into a check for either pointer
being NULL and if so just free both. This is safe since kfree() can
deal with being passed a NULL pointer and it avoids the leak.

While I was there I also removed the casts of the kmalloc() return
value since it's pointless.
I also updated the driver version since this patch changes the workings of
the code (however slightly).

This issue could probably be fixed a lot more elegantly, but the code
is a big mess IMHO and I just took the least intrusive route to a fix
that I could find instead of starting on a cleanup as well (that can
come later).

Please consider for inclusion.

Signed-off-by: Jesper Juhl 
Signed-off-by: James Bottomley

[PATCH] drivers/block/*: use time_after() and friends

2006-03-28T17:16:06+00:00

They deal with wrapping correctly and are nicer to read.

Signed-off-by: Marcelo Feitoza Parisi 
Signed-off-by: Alexey Dobriyan 
Cc: Jens Axboe 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] kzalloc() conversion in drivers/block

2006-03-27T07:29:02+00:00

this patch converts drivers/block to kzalloc usage.
Compile tested with allyesconfig.

Signed-off-by: Eric Sesterhenn 
Signed-off-by: Jens Axboe