[PATCH AUTOSEL 4.19 137/671] bus: ti-sysc: Fix timer handling with drop pm_runtime_irq_safe()

Sasha Levin
2020-01-16T19:11:31Z

From: Tony Lindgren <tony@atomide.com>

[ Upstream commit 9bd34c63f5536c490c152833c77fa47f59aeade3 ]

Commit 84badc5ec5fc ("ARM: dts: omap4: Move l4 child devices to probe
them with ti-sysc") started producing a warning for pwm-omap-dmtimer:

WARNING: CPU: 0 PID: 77 at drivers/bus/omap_l3_noc.c:147
l3_interrupt_handler+0x2f8/0x388
44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4PER2 (Idle):
Data Access in Supervisor mode during Functional access
...
__pm_runtime_idle
omap_dm_timer_disable
pwm_omap_dmtimer_start
pwm_omap_dmtimer_enable
pwm_apply_state
pwm_vibrator_start
pwm_vibrator_play_work

This is because the timer that pwm-omap-dmtimer is using is now being
probed with ti-sysc interconnect target module instead of omap_device
and the ti-sysc quirk for SYSC_QUIRK_LEGACY_IDLE is not fully
compatible with what omap_device has been doing.

We could fix this by reverting the timer changes and have the timer
probe again with omap_device. Or we could add more quirk handling to
ti-sysc driver. But as these options don't work nicely as longer term
solutions, let's just make timers probe with ti-sysc without any
quirks.

To do this, all we need to do is remove quirks for timers for ti-sysc,
and drop the bogus pm_runtime_irq_safe() flag for timer-ti-dm.

We should not use pm_runtime_irq_safe() anyways for drivers as it will
take a permanent use count on the parent device blocking the parent
devices from idling and has been forcing ti-sysc driver to use a
quirk flag.

Note that we will move the timer data to DEBUG section later on in
clean-up patches.

Fixes: 84badc5ec5fc ("ARM: dts: omap4: Move l4 child devices to probe them with ti-sysc")
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: H. Nikolaus Schaller <hns@goldelico.com>
Cc: Keerthy <j-keerthy@ti.com>
Cc: Ladislav Michl <ladis@linux-mips.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-By: Andreas Kemnade <andreas@kemnade.info>
Tested-By: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/bus/ti-sysc.c | 4 ++--
drivers/clocksource/timer-ti-dm.c | 1 -
2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c
index 926c83398b27..2813f9ed57c0 100644
--- a/drivers/bus/ti-sysc.c
+++ b/drivers/bus/ti-sysc.c
@@ -888,10 +888,10 @@ static const struct sysc_revision_quirk sysc_revision_quirks[] = {
SYSC_QUIRK("smartreflex", 0, -1, 0x38, -1, 0x00000000, 0xffffffff,
SYSC_QUIRK_LEGACY_IDLE),
SYSC_QUIRK("timer", 0, 0, 0x10, 0x14, 0x00000015, 0xffffffff,
- SYSC_QUIRK_LEGACY_IDLE),
+ 0),
/* Some timers on omap4 and later */
SYSC_QUIRK("timer", 0, 0, 0x10, -1, 0x4fff1301, 0xffffffff,
- SYSC_QUIRK_LEGACY_IDLE),
+ 0),
SYSC_QUIRK("uart", 0, 0x50, 0x54, 0x58, 0x00000052, 0xffffffff,
SYSC_QUIRK_LEGACY_IDLE),
/* Uarts on omap4 and later */
diff --git a/drivers/clocksource/timer-ti-dm.c b/drivers/clocksource/timer-ti-dm.c
index 3ecf84706640..23414dddc3ba 100644
--- a/drivers/clocksource/timer-ti-dm.c
+++ b/drivers/clocksource/timer-ti-dm.c
@@ -868,7 +868,6 @@ static int omap_dm_timer_probe(struct platform_device *pdev)
timer->pdev = pdev;

pm_runtime_enable(dev);
- pm_runtime_irq_safe(dev);

if (!timer->reserved) {
ret = pm_runtime_get_sync(dev);
--
2.20.1