From: Boris Brezillon Date: Thu, 25 Jun 2026 12:40:31 +0000 (+0200) Subject: drm/panthor: Fix theoretical IOMEM access in suspended state X-Git-Tag: v7.2-rc2~10^2^2~11 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fe4c05a59018964bac7923338706371fff3c09ef;p=thirdparty%2Fkernel%2Flinux.git drm/panthor: Fix theoretical IOMEM access in suspended state In theory, our hardirq handler can be called while the device (and thus the panthor_irq) is suspended, because the IRQ line is shared. In practice though, in all the designs we've seen, the line is only shared within the GPU, and because sub-component suspend state is consistent (all-suspended or all-resumed), we shouldn't end up with an interrupt triggered while we're suspended. Fix the problem anyway, if nothing else, for our sanity. Fixes: 0b2d86670a84 ("drm/panthor: Rework panthor_irq::suspended into panthor_irq::state") Reported-by: sashiko-bot@kernel.org Closes: https://sashiko.dev/#/patchset/20260625-panthor-signal-from-irq-v4-0-3d2908912afa@collabora.com?part=1 Signed-off-by: Boris Brezillon Reviewed-by: Liviu Dudau Signed-off-by: Liviu Dudau Link: https://patch.msgid.link/20260625-panthor-misc-fixes-v1-5-b67ed973fea6@collabora.com --- diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h index a412a50eec76..291e0de154bc 100644 --- a/drivers/gpu/drm/panthor/panthor_device.h +++ b/drivers/gpu/drm/panthor/panthor_device.h @@ -509,9 +509,6 @@ static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data) struct panthor_irq *pirq = data; \ enum panthor_irq_state old_state; \ \ - if (!gpu_read(pirq->iomem, INT_STAT)) \ - return IRQ_NONE; \ - \ guard(spinlock_irqsave)(&pirq->mask_lock); \ old_state = atomic_cmpxchg(&pirq->state, \ PANTHOR_IRQ_STATE_ACTIVE, \ @@ -519,6 +516,13 @@ static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data) if (old_state != PANTHOR_IRQ_STATE_ACTIVE) \ return IRQ_NONE; \ \ + if (!gpu_read(pirq->iomem, INT_STAT)) { \ + atomic_cmpxchg(&pirq->state, \ + PANTHOR_IRQ_STATE_PROCESSING, \ + PANTHOR_IRQ_STATE_ACTIVE); \ + return IRQ_NONE; \ + } \ + \ gpu_write(pirq->iomem, INT_MASK, 0); \ return IRQ_WAKE_THREAD; \ } \