On 14/06/17 10:19, Marc Gonzalez wrote:
> On 14/06/2017 11:00, Marc Gonzalez wrote:
>
>> The MSI controller in Tango supports 256 message-signaled interrupts,
>> and a single doorbell address.
>>
>> Signed-off-by: Marc Gonzalez <[email protected]>
>> ---
>> Changes from v6 to v7
>> o Call spin_lock() not spin_lock_irqsave() in the ISR
>> ---
>> drivers/pci/host/pcie-tango.c | 225
>> ++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 225 insertions(+)
>
> Someone on IRC suggested testing the driver with LOCKDEP.
>
> If I understand the warning below correctly, I am not supposed
> to call irq_domain_set_info() while holding used_msi_lock?
Indeed. This creates an AB/BA situation, which will eventually deadlock.
Once again, lockdep saves the day.
> NB: in probe, my driver calls
>
> add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
>
> This should not break LOCKDEP analysis, right?
It doesn't. The code is provably wrong, and lockdep proved that it is wrong.
M.
--
Jazz is not dead. It just smells funny...
