octeontx2-vf: clear stale mailbox IRQ state before request_irq()

otx2vf_register_mbox_intr() currently installs the VF mailbox IRQ
handler before clearing stale mailbox interrupt state. The code then says
that local interrupt bits should be cleared first to avoid spurious
interrupts, but that clear still happens only after request_irq() has
already made the handler reachable.

A running system can reach this during VF mailbox interrupt registration
while stale or latched RVU_VF_INT state is still present. If delivery
happens in the request_irq()-to-clear window,
otx2vf_vfaf_mbox_intr_handler() can run before local quiesce and touch
the same vf->mbox and vf->mbox_wq carrier that probe and teardown later
reuse or destroy.

Move the stale mailbox interrupt clear ahead of request_irq(), but keep
interrupt enabling after the handler is installed. This closes the
pre-clear early-IRQ window without creating a new enable-before-handler
window.

Fixes: 3184fb5ba96e ("octeontx2-vf: Virtual function driver support")
Cc: stable@vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Ratheesh Kannoth <rkannoth@marvell.com>
Link: https://patch.msgid.link/20260611160014.3202224-3-runyu.xiao@seu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions