Le jeu. 20 août 2020 à 20:23, Lars-Peter Clausen <lars@xxxxxxxxxx> a
écrit :
On 8/20/20 1:59 PM, Paul Cercueil wrote:
Hi,
Le dim. 16 août 2020 à 12:52, madhuparnabhowmik10@xxxxxxxxx a
écrit :
From: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
In probe IRQ is requested before zchan->id is initialized which can
be
read in the irq handler. Hence, shift request irq and enable clock
after
other initializations complete. Here, enable clock part is not part
of
the race, it is just shifted down after request_irq to keep the
error
path same as before.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
I don't think there is a race at all, the interrupt handler won't be
called before the DMA is registered.
From a purely formal verification perspective there is a bug. The
interrupt could fire if i.e. the hardware is buggy or something. In
general it is a good idea to not request the IRQ until all the
resources that are used in the interrupt handler are properly set up.
Even if you know that in practice the interrupt will never fire this
early.
Fair enough, I'm fine with that, but the patch should be reworked so
that the clk_prepare_enable() call is not moved.
Cheers,
-Paul
