linux-kernel - [PATCH] soc: apple: apple-pmgr-pwrstate: Switch to IRQ-safe mode

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Date:   Mon, 23 Jan 2023 15:51:25 +0900
From:   Hector Martin <marcan@...can.st>
To:     Sven Peter <sven@...npeter.dev>
Cc:     Alyssa Rosenzweig <alyssa@...enzweig.io>,
        Janne Grunau <j@...nau.net>, asahi@...ts.linux.dev,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Hector Martin <marcan@...can.st>
Subject: [PATCH] soc: apple: apple-pmgr-pwrstate: Switch to IRQ-safe mode

This requires changing the reset path locking primitives to the spinlock
path in genpd, instead of the mutex path.

Signed-off-by: Hector Martin <marcan@...can.st>
---
 drivers/soc/apple/apple-pmgr-pwrstate.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/soc/apple/apple-pmgr-pwrstate.c b/drivers/soc/apple/apple-pmgr-pwrstate.c
index e1122288409a..a3e2bc1d2686 100644
--- a/drivers/soc/apple/apple-pmgr-pwrstate.c
+++ b/drivers/soc/apple/apple-pmgr-pwrstate.c
@@ -116,8 +116,9 @@ static int apple_pmgr_ps_power_off(struct generic_pm_domain *genpd)
 static int apple_pmgr_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
 {
 	struct apple_pmgr_ps *ps = rcdev_to_apple_pmgr_ps(rcdev);
+	unsigned long flags;
 
-	mutex_lock(&ps->genpd.mlock);
+	spin_lock_irqsave(&ps->genpd.slock, flags);
 
 	if (ps->genpd.status == GENPD_STATE_OFF)
 		dev_err(ps->dev, "PS 0x%x: asserting RESET while powered down\n", ps->offset);
@@ -129,7 +130,7 @@ static int apple_pmgr_reset_assert(struct reset_controller_dev *rcdev, unsigned
 	regmap_update_bits(ps->regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_RESET,
 			   APPLE_PMGR_RESET);
 
-	mutex_unlock(&ps->genpd.mlock);
+	spin_unlock_irqrestore(&ps->genpd.slock, flags);
 
 	return 0;
 }
@@ -137,8 +138,9 @@ static int apple_pmgr_reset_assert(struct reset_controller_dev *rcdev, unsigned
 static int apple_pmgr_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
 {
 	struct apple_pmgr_ps *ps = rcdev_to_apple_pmgr_ps(rcdev);
+	unsigned long flags;
 
-	mutex_lock(&ps->genpd.mlock);
+	spin_lock_irqsave(&ps->genpd.slock, flags);
 
 	dev_dbg(ps->dev, "PS 0x%x: deassert reset\n", ps->offset);
 	regmap_update_bits(ps->regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_RESET, 0);
@@ -147,7 +149,7 @@ static int apple_pmgr_reset_deassert(struct reset_controller_dev *rcdev, unsigne
 	if (ps->genpd.status == GENPD_STATE_OFF)
 		dev_err(ps->dev, "PS 0x%x: RESET was deasserted while powered down\n", ps->offset);
 
-	mutex_unlock(&ps->genpd.mlock);
+	spin_unlock_irqrestore(&ps->genpd.slock, flags);
 
 	return 0;
 }
@@ -222,6 +224,7 @@ static int apple_pmgr_ps_probe(struct platform_device *pdev)
 		return ret;
 	}
 
+	ps->genpd.flags |= GENPD_FLAG_IRQ_SAFE;
 	ps->genpd.name = name;
 	ps->genpd.power_on = apple_pmgr_ps_power_on;
 	ps->genpd.power_off = apple_pmgr_ps_power_off;
-- 
2.35.1