On Mon, 2018-12-10 at 16:17 +0000, Lorenzo Pieralisi wrote:
> On Tue, Nov 13, 2018 at 10:57:31PM +0000, Marc Zyngier wrote:
> > It recently came to light that the Designware PCIe driver is rather
> > broken in the way it handles MSI[1]:
> >
> > - It masks interrupt by disabling them, meaning that MSIs generated
> > during the masked window are simply lost. Oops.
> >
> > - Acking of the currently pending MSI is done outside of the
> > interrupt
> > flow, getting moved around randomly and ultimately breaking the
> > driver. Not great.
> >
> >
> I have decided to queue this series - fixed-up as per this thread,
> available at:
>
> git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git
> test/pci-dwc-msi
>
> We allowed enough time for people to test it, we can't leave mainline
> broken for the, apparently few, people who care.
>
> I *think* that this is the Fixes: tag to be added to all patches in
> this
> series, @Gustavo please countercheck:
>
> 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains
> hierarchical API")
That's not the correct Fixes. It should be:
8c934095fa2f ("PCI: dwc: Clear MSI interrupt status after it is
handled, not before")
I had concerns about what appears to be an unnecessary extra lock taken
before handling an interrupt and enabling all MSIs even if nothing has
tried to enable them.
