d40_handle_interrupt() reads DMA40 interrupt registers unconditionally. A spurious interrupt can arrive while the device is runtime suspended, after dma40_runtime_suspend() has disabled the GCC clock.
Avoid touching the registers unless the device is runtime active by taking a conditional runtime PM reference. Return IRQ_NONE when the device is suspended, and drop the reference after handling an active interrupt. Reported-by: [email protected] Closes: https://lore.kernel.org/dmaengine/[email protected]/ Assisted-by: Codex:gpt-5-5 Signed-off-by: Linus Walleij <[email protected]> --- drivers/dma/ste_dma40.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c index facc1bcf42a0..dd449d4285ef 100644 --- a/drivers/dma/ste_dma40.c +++ b/drivers/dma/ste_dma40.c @@ -1674,6 +1674,11 @@ static irqreturn_t d40_handle_interrupt(int irq, void *data) u32 *regs = base->regs_interrupt; struct d40_interrupt_lookup *il = base->gen_dmac.il; u32 il_size = base->gen_dmac.il_size; + int ret; + + ret = pm_runtime_get_if_active(base->dev); + if (ret <= 0) + return IRQ_NONE; spin_lock(&base->interrupt_lock); @@ -1722,6 +1727,8 @@ static irqreturn_t d40_handle_interrupt(int irq, void *data) spin_unlock(&base->interrupt_lock); + pm_runtime_put_autosuspend(base->dev); + return IRQ_HANDLED; } -- 2.55.0
