[PATCH 5.10.y] media: microchip-isc: don't sleep in the clk .is_enabled callback

[Sasha Levin <sashal@kernel.org>]

From: Balakrishnan Sambath <balakrishnan.s@microchip.com>

[ Upstream commit 61490ff518c7b3ea3ff1cd16bbc012e9e4f1ab74 ]

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>
Reviewed-by: Eugen Hristev <ehristev@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>
[ sashal: adapted the existing ISC_ISPCK-only PM handling to use the older two-argument pm_runtime_get_if_active(dev, true) API ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/platform/atmel/atmel-isc-base.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/atmel/atmel-isc-base.c b/drivers/media/platform/atmel/atmel-isc-base.c
index fe3ec8d0eaee3..18b3517097de9 100644
--- a/drivers/media/platform/atmel/atmel-isc-base.c
+++ b/drivers/media/platform/atmel/atmel-isc-base.c
@@ -354,13 +354,15 @@ static int isc_clk_is_enabled(struct clk_hw *hw)
 	struct isc_clk *isc_clk = to_isc_clk(hw);
 	u32 status;
 
-	if (isc_clk->id == ISC_ISPCK)
-		pm_runtime_get_sync(isc_clk->dev);
+	/* Runs in atomic context, so must not sleep to resume the ISC. */
+	if (isc_clk->id == ISC_ISPCK &&
+	    pm_runtime_get_if_active(isc_clk->dev, true) <= 0)
+		return 0;
 
 	regmap_read(isc_clk->regmap, ISC_CLKSR, &status);
 
 	if (isc_clk->id == ISC_ISPCK)
-		pm_runtime_put_sync(isc_clk->dev);
+		pm_runtime_put(isc_clk->dev);
 
 	return status & ISC_CLK(isc_clk->id) ? 1 : 0;
 }
-- 
2.53.0