From 8c02722be2caa6604a837b81faeaba78250eda4a Mon Sep 17 00:00:00 2001 From: Javier Carrasco Date: Wed, 14 Oct 2026 19:34:10 +0200 Subject: [PATCH] hwmon: chipcap2: synchronize ready IRQ state The ready IRQ handler can race with reinit_completion() in the enable path. In particular, a handler from an earlier operation can complete the completion after it is reset for a new operation. Use irq_lock to serialize access to the completion and process_irqs. Disable IRQ processing and synchronize any running handler before resetting the completion for a new operation. Fixes: 3af350929e75 ("hwmon: Add support for Amphenol ChipCap 2") Cc: stable@vger.kernel.org Signed-off-by: Javier Carrasco Link: https://patch.msgid.link/20261014-chipcap2_locks-v3-11-27ebfc2c5b9e@gmail.com [groeck: Dropped obsolete 'Assisted-by: tag] Signed-off-by: Guenter Roeck --- drivers/hwmon/chipcap2.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/chipcap2.c b/drivers/hwmon/chipcap2.c index b3b725cc7224..00f62a33d463 100644 --- a/drivers/hwmon/chipcap2.c +++ b/drivers/hwmon/chipcap2.c @@ -123,6 +123,16 @@ static int cc2_enable(struct cc2_data *data) { int ret; + if (data->irq_ready > 0) { + scoped_guard(mutex, &data->irq_lock) + data->process_irqs = false; + + synchronize_irq(data->irq_ready); + + scoped_guard(mutex, &data->irq_lock) + reinit_completion(&data->complete); + } + /* exclusive regulator, check in case a disable failed */ if (data->regulator_enabled) { scoped_guard(mutex, &data->irq_lock) @@ -130,9 +140,6 @@ static int cc2_enable(struct cc2_data *data) return 0; } - /* clear any pending completion */ - try_wait_for_completion(&data->complete); - ret = regulator_enable(data->regulator); if (ret < 0) return ret; @@ -162,6 +169,9 @@ static void cc2_disable(struct cc2_data *data) scoped_guard(mutex, &data->irq_lock) data->process_irqs = false; + if (data->irq_ready > 0) + synchronize_irq(data->irq_ready); + /* exclusive regulator, check in case an enable failed */ if (!data->regulator_enabled) return; @@ -510,8 +520,10 @@ static irqreturn_t cc2_ready_interrupt(int irq, void *data) { struct cc2_data *cc2 = data; - if (cc2->process_irqs) - complete(&cc2->complete); + scoped_guard(mutex, &cc2->irq_lock) { + if (cc2->process_irqs) + complete(&cc2->complete); + } return IRQ_HANDLED; }