On Thu, 15 Jan 2026 14:58:59 +0100 Nicolas Frattaroli <[email protected]> wrote:
> To deal with the threaded interrupt handler and a suspend action > overlapping, the boolean panthor_irq::suspended is not sufficient. > > Rework it into taking several different values depending on the current > state, and check it and set it within the IRQ helper functions. > > Signed-off-by: Nicolas Frattaroli <[email protected]> > --- > drivers/gpu/drm/panthor/panthor_device.h | 32 > ++++++++++++++++++++++++++------ > 1 file changed, 26 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/panthor/panthor_device.h > b/drivers/gpu/drm/panthor/panthor_device.h > index f35e52b9546a..2bf9a8434dc5 100644 > --- a/drivers/gpu/drm/panthor/panthor_device.h > +++ b/drivers/gpu/drm/panthor/panthor_device.h > @@ -61,6 +61,17 @@ enum panthor_device_pm_state { > PANTHOR_DEVICE_PM_STATE_SUSPENDING, > }; > > +enum panthor_irq_state { > + /** @PANTHOR_IRQ_STATE_ACTIVE: IRQ is active and ready to process > events. */ > + PANTHOR_IRQ_STATE_ACTIVE = 0, > + /** @PANTHOR_IRQ_STATE_PROCESSING: IRQ is currently processing events. > */ > + PANTHOR_IRQ_STATE_PROCESSING, > + /** @PANTHOR_IRQ_STATE_SUSPENDED: IRQ is suspended. */ > + PANTHOR_IRQ_STATE_SUSPENDED, > + /** @PANTHOR_IRQ_STATE_SUSPENDING: IRQ is being suspended. */ > + PANTHOR_IRQ_STATE_SUSPENDING, > +}; > + > /** > * struct panthor_irq - IRQ data > * > @@ -76,8 +87,8 @@ struct panthor_irq { > /** @mask: Current mask being applied to xxx_INT_MASK. */ > u32 mask; > > - /** @suspended: Set to true when the IRQ is suspended. */ > - atomic_t suspended; > + /** @state: one of &enum panthor_irq_state reflecting the current > state. */ > + atomic_t state; > }; > > /** > @@ -409,8 +420,10 @@ static irqreturn_t panthor_ ## __name ## > _irq_raw_handler(int irq, void *data) > { > \ > struct panthor_irq *pirq = data; > \ > struct panthor_device *ptdev = pirq->ptdev; > \ > + enum panthor_irq_state state; > \ > > \ > - if (atomic_read(&pirq->suspended)) > \ > + state = atomic_read(&pirq->state); > \ > + if (state == PANTHOR_IRQ_STATE_SUSPENDED || state == > PANTHOR_IRQ_STATE_SUSPENDING) \ > return IRQ_NONE; > \ > if (!gpu_read(ptdev, __reg_prefix ## _INT_STAT)) > \ > return IRQ_NONE; > \ I was imagining something like: if (!gpu_read(ptdev, __reg_prefix ## _INT_STAT)) return IRQ_NONE; old_state = atomic_cmpxchg(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE, PANTHOR_IRQ_STATE_PROCESSING); if (old_state != PANTHOR_IRQ_STATE_ACTIVE) return IRQ_NONE; such that the processing phase starts as soon as we know we're going to wake up the irq thread, not when we enter the threaded handler. > @@ -423,8 +436,11 @@ static irqreturn_t panthor_ ## __name ## > _irq_threaded_handler(int irq, void *da > { > \ > struct panthor_irq *pirq = data; > \ > struct panthor_device *ptdev = pirq->ptdev; > \ > + enum panthor_irq_state state; > \ > irqreturn_t ret = IRQ_NONE; > \ > > \ > + atomic_cmpxchg(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE, > PANTHOR_IRQ_STATE_PROCESSING); \ I think this is better done in the raw_handler (see above). > + > \ > while (true) { > \ > u32 status = gpu_read(ptdev, __reg_prefix ## _INT_RAWSTAT) & > pirq->mask; \ > > \ > @@ -435,8 +451,11 @@ static irqreturn_t panthor_ ## __name ## > _irq_threaded_handler(int irq, void *da > ret = IRQ_HANDLED; > \ > } > \ > > \ > - if (!atomic_read(&pirq->suspended)) > \ > + state = atomic_read(&pirq->state); > \ > + if (state != PANTHOR_IRQ_STATE_SUSPENDED && state != > PANTHOR_IRQ_STATE_SUSPENDING) { \ > gpu_write(ptdev, __reg_prefix ## _INT_MASK, pirq->mask); > \ > + atomic_set(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE); > \ > + } > \ Similarly, I think I'd go for old_state = atomic_cmpxchg(&pirq->state, PANTHOR_IRQ_STATE_PROCESSING, PANTHOR_IRQ_STATE_ACTIVE); if (old_state == PANTHOR_IRQ_STATE_PROCESSING) gpu_write(ptdev, __reg_prefix ## _INT_MASK, pirq->mask); > > \ > return ret; > \ > } > \ > @@ -445,14 +464,15 @@ static inline void panthor_ ## __name ## > _irq_suspend(struct panthor_irq *pirq) > { > \ > pirq->mask = 0; > \ > gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, 0); > \ > + atomic_set(&pirq->state, PANTHOR_IRQ_STATE_SUSPENDING); > \ > synchronize_irq(pirq->irq); > \ > - atomic_set(&pirq->suspended, true); > \ > + atomic_set(&pirq->state, PANTHOR_IRQ_STATE_SUSPENDED); > \ > } > \ > > \ > static inline void panthor_ ## __name ## _irq_resume(struct panthor_irq > *pirq, u32 mask) \ > { > \ > - atomic_set(&pirq->suspended, false); > \ > pirq->mask = mask; > \ > + atomic_set(&pirq->state, PANTHOR_IRQ_STATE_ACTIVE); > \ > gpu_write(pirq->ptdev, __reg_prefix ## _INT_CLEAR, mask); > \ > gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, mask); > \ > } > \ >
