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  1. 20 9月, 2014 9 次提交
  3. 19 9月, 2014 1 次提交
    • P
      eeepc-laptop: simplify parse_arg() · 95369a73
      由 Paul Bolle 提交于 
      parse_arg() has three possible return values:
    -EINVAL if sscanf(), in short, fails;
    zero if "count" is zero; and
    "count" in all other cases

But "count" will never be zero. See, parse_arg() is called by the
various store functions. And the callchain of these functions starts
with sysfs_kf_write(). And that function checks for a zero "count". So
we can stop checking for a zero "count", drop the "count" argument
entirely, and transform parse_arg() into a function that returns zero on
success or a negative error. That, in turn, allows to make those store
functions just return "count" on success. The net effect is that the
code becomes a bit easier to understand.

A nice side effect is that this GCC warning is silenced too:
    drivers/platform/x86/eeepc-laptop.c: In function ‘store_sys_acpi’:
    drivers/platform/x86/eeepc-laptop.c:279:10: warning: ‘value’ may be used uninitialized in this function [-Wmaybe-uninitialized]
      int rv, value;

Which is, of course, the reason to have a look at parse_arg().
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NDarren Hart <dvhart@linux.intel.com>
      95369a73
  5. 18 9月, 2014 7 次提交
  7. 14 9月, 2014 3 次提交
  9. 12 9月, 2014 8 次提交
  11. 11 9月, 2014 10 次提交
  13. 10 9月, 2014 2 次提交
    • A
      dm cache: fix race causing dirty blocks to be marked as clean · 40aa978e
      由 Anssi Hannula 提交于 
      When a writeback or a promotion of a block is completed, the cell of
that block is removed from the prison, the block is marked as clean, and
the clear_dirty() callback of the cache policy is called.

Unfortunately, performing those actions in this order allows an incoming
new write bio for that block to come in before clearing the dirty status
is completed and therefore possibly causing one of these two scenarios:

Scenario A:

Thread 1                      Thread 2
cell_defer()                  .
- cell removed from prison    .
- detained bios queued        .
.                             incoming write bio
.                             remapped to cache
.                             set_dirty() called,
.                               but block already dirty
.                               => it does nothing
clear_dirty()                 .
- block marked clean          .
- policy clear_dirty() called .

Result: Block is marked clean even though it is actually dirty. No
writeback will occur.

Scenario B:

Thread 1                      Thread 2
cell_defer()                  .
- cell removed from prison    .
- detained bios queued        .
clear_dirty()                 .
- block marked clean          .
.                             incoming write bio
.                             remapped to cache
.                             set_dirty() called
.                             - block marked dirty
.                             - policy set_dirty() called
- policy clear_dirty() called .

Result: Block is properly marked as dirty, but policy thinks it is clean
and therefore never asks us to writeback it.
This case is visible in "dmsetup status" dirty block count (which
normally decreases to 0 on a quiet device).

Fix these issues by calling clear_dirty() before calling cell_defer().
Incoming bios for that block will then be detained in the cell and
released only after clear_dirty() has completed, so the race will not
occur.

Found by inspecting the code after noticing spurious dirty counts
(scenario B).
Signed-off-by: NAnssi Hannula <anssi.hannula@iki.fi>
Acked-by: NJoe Thornber <ejt@redhat.com>
Signed-off-by: NMike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
      40aa978e
    • M
      pinctrl: baytrail: resolve unbalanced IRQ wake disable warning · 41939e69
      由 Mathias Nyman 提交于 
      Add the IRQCHIP_SKIP_SET_WAKE flag to baytrail gpio irq_chip
to resolve unbalaced IRQ wake disable warnings.
Suggested-by: NBorun Fu <borun.fu@intel.com>
Signed-off-by: NMathias Nyman <mathias.nyman@linux.intel.com>
Reviewed-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
      41939e69