diff options
author | NeilBrown <neilb@suse.de> | 2013-03-19 12:38:15 -0500 |
---|---|---|
committer | Benoit Cousson <benoit.cousson@linaro.org> | 2013-04-09 00:21:29 +0200 |
commit | 9cc268d5bbc097ae5a3ae236fb2461ea113274bf (patch) | |
tree | 05751016c7bde8b73ee2fbe6564ddb6bd1fb8db0 /arch/arm | |
parent | 7b3754c63e8d6528002386b313c527a826236d82 (diff) | |
download | linux-9cc268d5bbc097ae5a3ae236fb2461ea113274bf.tar.bz2 |
ARM: OMAP: Simplify dmtimer context-loss handling
The context loss handling in dmtimer appears to assume that
omap_dm_timer_set_load_start() or omap_dm_timer_start() and
omap_dm_timer_stop() bracket all interactions. Only the first two
restore the context and the last updates the context loss counter.
However omap_dm_timer_set_load() or omap_dm_timer_set_match() can
reasonably be called outside this bracketing, and the fact that they
call omap_dm_timer_enable() / omap_dm_timer_disable() suggest that
is expected.
So if, after a transition into and out of off-mode which would cause
the dm timer to loose all state, omap_dm_timer_set_match() is called
before omap_dm_timer_start(), the value read from OMAP_TIMER_CTRL_REG
will be 'wrong' and this wrong value will be stored context.tclr so
a subsequent omap_dm_timer_start() can fail (As the control register
is wrong).
Simplify this be doing the restore-from-context in
omap_dm_timer_enable() so that whenever the timer is enabled, the
context is correct. Also update the ctx_loss_count at the same time as
we notice it is wrong - these is no value in delaying this until the
omap_dm_timer_disable() as it cannot change while the timer is enabled.
Signed-off-by: NeilBrown <neilb@suse.de>
[jon-hunter@ti.com: minor update to subject and changed variable name]
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>
Diffstat (limited to 'arch/arm')
-rw-r--r-- | arch/arm/plat-omap/dmtimer.c | 32 |
1 files changed, 12 insertions, 20 deletions
diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c index a0daa2fb5de6..5cae1dd1f365 100644 --- a/arch/arm/plat-omap/dmtimer.c +++ b/arch/arm/plat-omap/dmtimer.c @@ -315,7 +315,19 @@ EXPORT_SYMBOL_GPL(omap_dm_timer_free); void omap_dm_timer_enable(struct omap_dm_timer *timer) { + int c; + pm_runtime_get_sync(&timer->pdev->dev); + + if (!(timer->capability & OMAP_TIMER_ALWON)) { + if (timer->get_context_loss_count) { + c = timer->get_context_loss_count(&timer->pdev->dev); + if (c != timer->ctx_loss_count) { + omap_timer_restore_context(timer); + timer->ctx_loss_count = c; + } + } + } } EXPORT_SYMBOL_GPL(omap_dm_timer_enable); @@ -410,13 +422,6 @@ int omap_dm_timer_start(struct omap_dm_timer *timer) omap_dm_timer_enable(timer); - if (!(timer->capability & OMAP_TIMER_ALWON)) { - if (timer->get_context_loss_count && - timer->get_context_loss_count(&timer->pdev->dev) != - timer->ctx_loss_count) - omap_timer_restore_context(timer); - } - l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG); if (!(l & OMAP_TIMER_CTRL_ST)) { l |= OMAP_TIMER_CTRL_ST; @@ -441,12 +446,6 @@ int omap_dm_timer_stop(struct omap_dm_timer *timer) __omap_dm_timer_stop(timer, timer->posted, rate); - if (!(timer->capability & OMAP_TIMER_ALWON)) { - if (timer->get_context_loss_count) - timer->ctx_loss_count = - timer->get_context_loss_count(&timer->pdev->dev); - } - /* * Since the register values are computed and written within * __omap_dm_timer_stop, we need to use read to retrieve the @@ -553,13 +552,6 @@ int omap_dm_timer_set_load_start(struct omap_dm_timer *timer, int autoreload, omap_dm_timer_enable(timer); - if (!(timer->capability & OMAP_TIMER_ALWON)) { - if (timer->get_context_loss_count && - timer->get_context_loss_count(&timer->pdev->dev) != - timer->ctx_loss_count) - omap_timer_restore_context(timer); - } - l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG); if (autoreload) { l |= OMAP_TIMER_CTRL_AR; |