Revision 2b95550a4323e501e133dac1c9c9cad6ff17f4c1 authored by Linus Torvalds on 11 February 2017, 17:15:58 UTC, committed by Linus Torvalds on 11 February 2017, 17:15:58 UTC
Pull btrfs fixes from Chris Mason:
 "This has two last minute fixes. The highest priority here is a
  regression fix for the decompression code, but we also fixed up a
  problem with the 32-bit compat ioctls.

  The decompression bug could hand back the wrong data on big reads when
  zlib was used. I have a larger cleanup to make the math here less
  error prone, but at this stage in the release Omar's patch is the best
  choice"

* 'for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: fix btrfs_decompress_buf2page()
  btrfs: fix btrfs_compat_ioctl failures on non-compat ioctls
2 parent s 13ebfd0 + 6e78b3f
Raw File
IRQ.txt
What is an IRQ?

An IRQ is an interrupt request from a device.
Currently they can come in over a pin, or over a packet.
Several devices may be connected to the same pin thus
sharing an IRQ.

An IRQ number is a kernel identifier used to talk about a hardware
interrupt source.  Typically this is an index into the global irq_desc
array, but except for what linux/interrupt.h implements the details
are architecture specific.

An IRQ number is an enumeration of the possible interrupt sources on a
machine.  Typically what is enumerated is the number of input pins on
all of the interrupt controller in the system.  In the case of ISA
what is enumerated are the 16 input pins on the two i8259 interrupt
controllers.

Architectures can assign additional meaning to the IRQ numbers, and
are encouraged to in the case  where there is any manual configuration
of the hardware involved.  The ISA IRQs are a classic example of
assigning this kind of additional meaning.
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