diff options
author | Paul Mundt <lethal@linux-sh.org> | 2011-05-31 15:23:20 +0900 |
---|---|---|
committer | Paul Mundt <lethal@linux-sh.org> | 2011-05-31 15:23:20 +0900 |
commit | d4905ce38c73964b868037e49a5945e1cf47a7f2 (patch) | |
tree | f7b41c1720dabb7b14a92ff0c47aeff1d6e4d70f /drivers/clocksource | |
parent | db7eba292e913390fa881272bfbc3da0a5380513 (diff) | |
download | lwn-d4905ce38c73964b868037e49a5945e1cf47a7f2.tar.gz lwn-d4905ce38c73964b868037e49a5945e1cf47a7f2.zip |
Revert "clocksource: sh_tmu: Runtime PM support"
This reverts commit 1b842e91fea9447eff5eb687e28ad61c02f5033e.
There is a fundamental ordering race between the early and late probe
paths and the runtime PM tie-in that results in __pm_runtime_resume()
attempting to take a lock that hasn't been initialized yet (which by
proxy also suggests that pm_runtime_init() hasn't yet been run on the
device either, making the entire thing unsafe) -- resulting in instant
death on SMP or on UP with spinlock debugging enabled:
sh_tmu.0: used for clock events
sh_tmu.0: used for periodic clock events
BUG: spinlock trylock failure on UP on CPU#0, swapper/0
lock: 804db198, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
...
Revert it for now until the ordering issues can be resolved, or we can get
some more help from the runtime PM framework to make this possible.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r-- | drivers/clocksource/sh_tmu.c | 12 |
1 files changed, 2 insertions, 10 deletions
diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c index 17296288a205..808135768617 100644 --- a/drivers/clocksource/sh_tmu.c +++ b/drivers/clocksource/sh_tmu.c @@ -25,7 +25,6 @@ #include <linux/delay.h> #include <linux/io.h> #include <linux/clk.h> -#include <linux/pm_runtime.h> #include <linux/irq.h> #include <linux/err.h> #include <linux/clocksource.h> @@ -110,12 +109,10 @@ static int sh_tmu_enable(struct sh_tmu_priv *p) { int ret; - /* wake up device and enable clock */ - pm_runtime_get_sync(&p->pdev->dev); + /* enable clock */ ret = clk_enable(p->clk); if (ret) { dev_err(&p->pdev->dev, "cannot enable clock\n"); - pm_runtime_put_sync(&p->pdev->dev); return ret; } @@ -144,9 +141,8 @@ static void sh_tmu_disable(struct sh_tmu_priv *p) /* disable interrupts in TMU block */ sh_tmu_write(p, TCR, 0x0000); - /* stop clock and mark device as idle */ + /* stop clock */ clk_disable(p->clk); - pm_runtime_put_sync(&p->pdev->dev); } static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta, @@ -415,7 +411,6 @@ static int __devinit sh_tmu_probe(struct platform_device *pdev) if (p) { dev_info(&pdev->dev, "kept as earlytimer\n"); - pm_runtime_enable(&pdev->dev); return 0; } @@ -430,9 +425,6 @@ static int __devinit sh_tmu_probe(struct platform_device *pdev) kfree(p); platform_set_drvdata(pdev, NULL); } - - if (!is_early_platform_device(pdev)) - pm_runtime_enable(&pdev->dev); return ret; } |