On Sat, Sep 05, 2026 at 12:57:34AM +0000, [email protected] wrote: > Thank you for your contribution! Sashiko AI review found 1 potential issue(s) > to consider: > > Pre-existing issues: > - [High] IRQ handler accesses hardware registers while device may be > suspended. > -- > > commit db83f58315d24bc892c6b008ce7d120f57ecaff1 > Author: Rob Herring (Arm) <[email protected]> > > accel: ethosu: Suspend after initialization > > The initial runtime-PM reference is held only while initializing the NPU. > Release it synchronously from ethosu_init() after the final hardware > access, before registering the DRM device. > > > diff --git a/drivers/accel/ethosu/ethosu_drv.c > > b/drivers/accel/ethosu/ethosu_drv.c > > index 8108622de258f..df76253d01a64 100644 > > --- a/drivers/accel/ethosu/ethosu_drv.c > > +++ b/drivers/accel/ethosu/ethosu_drv.c > > @@ -338,6 +338,8 @@ static int ethosu_init(struct ethosu_device *ethosudev) > > ethosudev->npu_info.sram_size / 1024, > > ethosudev->npu_info.pmu_counters); > > > > + pm_runtime_put_sync_suspend(ethosudev->base.dev); > > [Severity: High] > This isn't a bug introduced by this patch, but does putting the device into > an immediate synchronous suspend here expose a vulnerability in the interrupt > handler? > > Looking at ethosu_job_irq_handler() in drivers/accel/ethosu/ethosu_job.c: > > static irqreturn_t ethosu_job_irq_handler(int irq, void *data) > { > struct ethosu_device *dev = data; > u32 status = readl_relaxed(dev->regs + NPU_REG_STATUS); > ... > } > > The hardirq handler accesses hardware registers unconditionally without > verifying the device's PM state. > > If a spurious interrupt occurs while the device is in the RPM_SUSPENDED > state (where clocks are disabled via ethosu_device_suspend()), could > reading NPU_REG_STATUS cause a Synchronous External Abort? > > The PM subsystem guidelines mandate using pm_runtime_get_if_active() in > IRQ handlers to prevent accessing powered-off hardware registers.
Not an issue. The h/w will only generate an interrupt if a job has been submitted in which case we are not suspended. Rob
