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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 14:50:51 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-05 14:50:51 -0700 |
commit | 41844e36206be90cd4d962ea49b0abc3612a99d0 (patch) | |
tree | ce0b3a3403bc6abdb28f52779d0d7b57a51a5c86 /drivers/staging/unisys/visorbus/periodic_work.c | |
parent | 5691f0e9a3e7855832d5fd094801bf600347c2d0 (diff) | |
parent | fc1e2c8ea85e109acf09e74789e9b852f6eed251 (diff) | |
download | op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.zip op-kernel-dev-41844e36206be90cd4d962ea49b0abc3612a99d0.tar.gz |
Merge tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging and IIO updates from Greg KH:
"Here is the big staging and IIO driver pull request for 4.9-rc1.
There are a lot of patches in here, the majority due to the
drivers/staging/greybus/ subsystem being merged in with full
development history that went back a few years, in order to preserve
the work that those developers did over time.
Lots and lots of tiny cleanups happened in the tree as well, due to
the Outreachy application process and lots of other developers showing
up for the first time to clean code up. Along with those changes, we
deleted a wireless driver, and added a raspberrypi driver (currently
marked broken), and lots of new iio drivers.
Overall the tree still shrunk with more lines removed than added,
about 10 thousand lines removed in total. Full details are in the very
long shortlog below.
All of this has been in the linux-next tree with no issues. There will
be some merge problems with other subsystem trees, but those are all
minor problems and shouldn't be hard to work out when they happen
(MAINTAINERS and some lustre build problems with the IB tree)"
And furter from me asking for clarification about greybus:
"Right now there is a phone from Motorola shipping with this code (a
slightly older version, but the same tree), so even though Ara is not
alive in the same form, the functionality is happening. We are working
with the developers of that phone to merge the newer stuff in with
their fork so they can use the upstream version in future versions of
their phone product line.
Toshiba has at least one chip shipping in their catalog that
needs/uses this protocol over a Unipro link, and rumor has it that
there might be more in the future.
There are also other users of the greybus protocols, there is a talk
next week at ELC that shows how it is being used across a network
connection to control a device, and previous ELC talks have showed the
protocol stack being used over USB to drive embedded Linux boards.
I've also talked to some people who are starting to work to add a host
controller driver to control arduinos as the greybus PHY protocols are
very useful to control a serial/i2c/spio/whatever device across a
random physical link, as it is a way to have a self-describing device
be attached to a host without needing manual configuration.
So yes, people are using it, and there is still the chance that it
will show up in a phone/laptop/tablet/whatever from Google in the
future as well, the tech isn't dead, even if the original large phone
project happens to be"
* tag 'staging-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (3703 commits)
Staging: fbtft: Fix bug in fbtft-core
staging: rtl8188eu: fix double unlock error in rtw_resume_process()
staging:r8188eu: remove GEN_MLME_EXT_HANDLER macro
staging:r8188eu: remove GEN_DRV_CMD_HANDLER macro
staging:r8188eu: remove GEN_EVT_CODE macro
staging:r8188eu: remove GEN_CMD_CODE macro
staging:r8188eu: remove pkt_newalloc member of the recv_buf structure
staging:r8188eu: remove rtw_handle_dualmac declaration
staging:r8188eu: remove (RGTRY|BSSID)_(OFT|SZ) macros
staging:r8188eu: change rtl8188e_process_phy_info function argument type
Staging: fsl-mc: Remove blank lines
Staging: fsl-mc: Fix unaligned * in block comments
Staging: comedi: Align the * in block comments
Staging : ks7010 : Fix block comments warninig
Staging: vt6655: Remove explicit NULL comparison using Coccinelle
staging: rtl8188eu: core: rtw_xmit: Use macros instead of constants
staging: rtl8188eu: core: rtw_xmit: Move constant of the right side
staging: dgnc: Fix lines longer than 80 characters
Staging: dgnc: constify attribute_group structures
Staging: most: hdm-dim2: constify attribute_group structures
...
Diffstat (limited to 'drivers/staging/unisys/visorbus/periodic_work.c')
-rw-r--r-- | drivers/staging/unisys/visorbus/periodic_work.c | 204 |
1 files changed, 0 insertions, 204 deletions
diff --git a/drivers/staging/unisys/visorbus/periodic_work.c b/drivers/staging/unisys/visorbus/periodic_work.c deleted file mode 100644 index 00b1527..0000000 --- a/drivers/staging/unisys/visorbus/periodic_work.c +++ /dev/null @@ -1,204 +0,0 @@ -/* periodic_work.c - * - * Copyright (C) 2010 - 2015 UNISYS CORPORATION - * All rights reserved. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for more - * details. - */ - -/* - * Helper functions to schedule periodic work in Linux kernel mode. - */ -#include <linux/sched.h> - -#include "periodic_work.h" - -#define MYDRVNAME "periodic_work" - -struct periodic_work { - rwlock_t lock; - struct delayed_work work; - void (*workfunc)(void *); - void *workfuncarg; - bool is_scheduled; - bool want_to_stop; - ulong jiffy_interval; - struct workqueue_struct *workqueue; - const char *devnam; -}; - -static void periodic_work_func(struct work_struct *work) -{ - struct periodic_work *pw; - - pw = container_of(work, struct periodic_work, work.work); - (*pw->workfunc)(pw->workfuncarg); -} - -struct periodic_work -*visor_periodic_work_create(ulong jiffy_interval, - struct workqueue_struct *workqueue, - void (*workfunc)(void *), - void *workfuncarg, - const char *devnam) -{ - struct periodic_work *pw; - - pw = kzalloc(sizeof(*pw), GFP_KERNEL | __GFP_NORETRY); - if (!pw) - return NULL; - - rwlock_init(&pw->lock); - pw->jiffy_interval = jiffy_interval; - pw->workqueue = workqueue; - pw->workfunc = workfunc; - pw->workfuncarg = workfuncarg; - pw->devnam = devnam; - return pw; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_create); - -void visor_periodic_work_destroy(struct periodic_work *pw) -{ - kfree(pw); -} -EXPORT_SYMBOL_GPL(visor_periodic_work_destroy); - -/** Call this from your periodic work worker function to schedule the next - * call. - * If this function returns false, there was a failure and the - * periodic work is no longer scheduled - */ -bool visor_periodic_work_nextperiod(struct periodic_work *pw) -{ - bool rc = false; - - write_lock(&pw->lock); - if (pw->want_to_stop) { - pw->is_scheduled = false; - pw->want_to_stop = false; - rc = true; /* yes, true; see visor_periodic_work_stop() */ - goto unlock; - } else if (!queue_delayed_work(pw->workqueue, &pw->work, - pw->jiffy_interval)) { - pw->is_scheduled = false; - rc = false; - goto unlock; - } - rc = true; -unlock: - write_unlock(&pw->lock); - return rc; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_nextperiod); - -/** This function returns true iff new periodic work was actually started. - * If this function returns false, then no work was started - * (either because it was already started, or because of a failure). - */ -bool visor_periodic_work_start(struct periodic_work *pw) -{ - bool rc = false; - - write_lock(&pw->lock); - if (pw->is_scheduled) { - rc = false; - goto unlock; - } - if (pw->want_to_stop) { - rc = false; - goto unlock; - } - INIT_DELAYED_WORK(&pw->work, &periodic_work_func); - if (!queue_delayed_work(pw->workqueue, &pw->work, - pw->jiffy_interval)) { - rc = false; - goto unlock; - } - pw->is_scheduled = true; - rc = true; -unlock: - write_unlock(&pw->lock); - return rc; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_start); - -/** This function returns true iff your call actually stopped the periodic - * work. - * - * -- PAY ATTENTION... this is important -- - * - * NO NO #1 - * - * Do NOT call this function from some function that is running on the - * same workqueue as the work you are trying to stop might be running - * on! If you violate this rule, visor_periodic_work_stop() MIGHT work, - * but it also MIGHT get hung up in an infinite loop saying - * "waiting for delayed work...". This will happen if the delayed work - * you are trying to cancel has been put in the workqueue list, but can't - * run yet because we are running that same workqueue thread right now. - * - * Bottom line: If you need to call visor_periodic_work_stop() from a - * workitem, be sure the workitem is on a DIFFERENT workqueue than the - * workitem that you are trying to cancel. - * - * If I could figure out some way to check for this "no no" condition in - * the code, I would. It would have saved me the trouble of writing this - * long comment. And also, don't think this is some "theoretical" race - * condition. It is REAL, as I have spent the day chasing it. - * - * NO NO #2 - * - * Take close note of the locks that you own when you call this function. - * You must NOT own any locks that are needed by the periodic work - * function that is currently installed. If you DO, a deadlock may result, - * because stopping the periodic work often involves waiting for the last - * iteration of the periodic work function to complete. Again, if you hit - * this deadlock, you will get hung up in an infinite loop saying - * "waiting for delayed work...". - */ -bool visor_periodic_work_stop(struct periodic_work *pw) -{ - bool stopped_something = false; - - write_lock(&pw->lock); - stopped_something = pw->is_scheduled && (!pw->want_to_stop); - while (pw->is_scheduled) { - pw->want_to_stop = true; - if (cancel_delayed_work(&pw->work)) { - /* We get here if the delayed work was pending as - * delayed work, but was NOT run. - */ - WARN_ON(!pw->is_scheduled); - pw->is_scheduled = false; - } else { - /* If we get here, either the delayed work: - * - was run, OR, - * - is running RIGHT NOW on another processor, OR, - * - wasn't even scheduled (there is a miniscule - * timing window where this could be the case) - * flush_workqueue() would make sure it is finished - * executing, but that still isn't very useful, which - * explains the loop... - */ - } - if (pw->is_scheduled) { - write_unlock(&pw->lock); - schedule_timeout_interruptible(msecs_to_jiffies(10)); - write_lock(&pw->lock); - } else { - pw->want_to_stop = false; - } - } - write_unlock(&pw->lock); - return stopped_something; -} -EXPORT_SYMBOL_GPL(visor_periodic_work_stop); |