[PATCH] media: microchip-isc: don't sleep in the clk .is_enabled callback

[PATCH] media: microchip-isc: don't sleep in the clk .is_enabled callback

[Balakrishnan Sambath]

isc_clk_is_enabled() calls pm_runtime_resume_and_get() and
pm_runtime_put_sync(), which can sleep and are not safe here, as
.is_enabled must run in atomic context. clk_disable_unused() calls it so
at boot, and CONFIG_DEBUG_ATOMIC_SLEEP reports a "sleeping function
called from invalid context" BUG.

Use the atomic-safe pm_runtime_get_if_active() and pm_runtime_put()
instead. A suspended ISC has its clocks gated, so report the clock
disabled when the device is not already active.

Fixes: 01192aa1c5c2 ("media: atmel-isc: Enable the clocks during probe")
Cc: stable@vger.kernel.org
Signed-off-by: Balakrishnan Sambath <balakrishnan.s@microchip.com>
---
 drivers/media/platform/microchip/microchip-isc-clk.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/microchip/microchip-isc-clk.c b/drivers/media/platform/microchip/microchip-isc-clk.c
index 24358d804e75..66dc522a6190 100644
--- a/drivers/media/platform/microchip/microchip-isc-clk.c
+++ b/drivers/media/platform/microchip/microchip-isc-clk.c
@@ -98,15 +98,14 @@ static int isc_clk_is_enabled(struct clk_hw *hw)
 {
 	struct isc_clk *isc_clk = to_isc_clk(hw);
 	u32 status;
-	int ret;
 
-	ret = pm_runtime_resume_and_get(isc_clk->dev);
-	if (ret < 0)
+	/* Runs in atomic context, so must not sleep to resume the ISC. */
+	if (pm_runtime_get_if_active(isc_clk->dev) <= 0)
 		return 0;
 
 	regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
 
-	pm_runtime_put_sync(isc_clk->dev);
+	pm_runtime_put(isc_clk->dev);
 
 	return status & ISC_CLK(isc_clk->id) ? 1 : 0;
 }

base-commit: 05f7e89ab9731565d8a62e3b5d1ec206485eeb0b
-- 
2.34.1