linux-toradex.git/kernel/async.c, branch tegra-10.9.4

async: Fix lack of boot-time console due to insufficient synchronization

2009-06-08T19:31:53+00:00

Our async work synchronization was broken by "async: make sure
independent async domains can't accidentally entangle" (commit
d5a877e8dd409d8c702986d06485c374b705d340), because it would report
the wrong lowest active async ID when there was both running and
pending async work.

This caused things like no being able to read the root filesystem,
resulting in missing console devices and inability to run 'init',
causing a boot-time panic.

This fixes it by properly returning the lowest pending async ID: if
there is any running async work, that will have a lower ID than any
pending work, and we should _not_ look at the pending work list.

There were alternative patches from Jaswinder and James, but this one
also cleans up the code by removing the pointless 'ret' variable and
the unnecesary testing for an empty list around 'for_each_entry()' (if
the list is empty, the for_each_entry() thing just won't execute).

Fixes-bug: http://bugzilla.kernel.org/show_bug.cgi?id=13474
Reported-and-tested-by: Chris Clayton 
Cc: Jaswinder Singh Rajput 
Cc: James Bottomley 
Cc: Arjan van de Ven 
Signed-off-by: Linus Torvalds

async: make sure independent async domains can't accidentally entangle

2009-05-24T20:38:41+00:00

The problem occurs when async_synchronize_full_domain() is called when
the async_pending list is not empty.  This will cause lowest_running()
to return the cookie of the first entry on the async_pending list, which
might be nothing at all to do with the domain being asked for and thus
cause the domain synchronization to wait for an unrelated domain.   This
can cause a deadlock if domain synchronization is used from one domain
to wait for another.

Fix by running over the async_pending list to see if any pending items
actually belong to our domain (and return their cookies if they do).

Signed-off-by: James Bottomley 
Signed-off-by: Arjan van de Ven 
Signed-off-by: Linus Torvalds

async: remove the temporary (2.6.29) "async is off by default" code

2009-03-28T20:05:30+00:00

Now that everyone has been able to test the async code (and it's being used
in the Moblin betas by default), we can enable it by default.
The various fixes needed have gone into 2.6.29 already.

[With an important bugfix from Stefan Richter]

Signed-off-by: Arjan van de Ven

async: use list_move_tail

2009-02-08T18:00:26+00:00

list.h provides a dedicated primitive for
"list_del followed by list_add_tail"... list_move_tail.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Stefan Richter

async: Rename _special -> _domain for clarity.

2009-02-08T17:56:11+00:00

Rename the async_*_special() functions to async_*_domain(), which
describes the purpose of these functions much better.
[Broke up long lines to silence checkpatch]

Signed-off-by: Cornelia Huck 
Signed-off-by: Arjan van de Ven

async: Add some documentation.

2009-02-08T17:56:11+00:00

Add some kerneldoc to the async interface.

Signed-off-by: Cornelia Huck 
Signed-off-by: Arjan van de Ven

async: Handle kthread_run() return codes.

2009-02-08T17:56:10+00:00

If we fail to create the manager thread, fall back to non-fastboot.
If we fail to create an async thread, try again after waiting for
a bit.

Signed-off-by: Cornelia Huck 
Signed-off-by: Arjan van de Ven

async: Fix running list handling.

2009-02-08T17:56:10+00:00

async_schedule() should pass in async_running as the running
list, and run_one_entry() should put the entry to be run on
the provided running list instead of always on the generic one.

Reported-by: Jonathan Corbet 
Signed-off-by: Cornelia Huck 
Signed-off-by: Arjan van de Ven

kernel/async.c: fix printk warnings

2009-02-05T20:56:46+00:00

alpha:

kernel/async.c: In function 'run_one_entry':
kernel/async.c:141: warning: format '%lli' expects type 'long long int', but argument 2 has type 'async_cookie_t'
kernel/async.c:149: warning: format '%lli' expects type 'long long int', but argument 2 has type 'async_cookie_t'
kernel/async.c:149: warning: format '%lld' expects type 'long long int', but argument 4 has type 's64'
kernel/async.c: In function 'async_synchronize_cookie_special':
kernel/async.c:250: warning: format '%lli' expects type 'long long int', but argument 3 has type 's64'

Cc: Arjan van de Ven 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

async: fix __lowest_in_progress()

2009-01-13T00:39:58+00:00

At 37000 feet somewhere near Greenland I woke up from a half-sleep with the
realisation that __lowest_in_progress() is buggy. After landing I checked
and there were indeed 2 problems with it; this patch fixes both:
* The order of the list checks was wrong
* The locking was not correct.

Signed-off-by: Arjan van de Ven 
Signed-off-by: Linus Torvalds