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. > > This series attempts to address this by switching to using the MASK > register for masking interrupts (!), and move the ack into the > appropriate callback, giving it a fixed place in the MSI handling > flow. > > Note that this is only compile-tested on my arm64 laptop, as I'm > travelling and do not have the required HW to test it anyway. I'd > welcome both review and testing by the interested parties (dwc > maintainer and users affected by existing bugs). > > Thanks, > > M. > > [1] https://patchwork.kernel.org/patch/10657987/ > > Marc Zyngier (3): > PCI: designware: Use interrupt masking instead of disabling > PCI: designware: Take lock when ACKing an interrupt > PCI: designware: Move interrupt acking into the proper callback > > .../pci/controller/dwc/pcie-designware-host.c | 22 ++++++++++++------- > 1 file changed, 14 insertions(+), 8 deletions(-) Marc, Gustavo, 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") I will mark them for stable too and we will work on backports to be sent in due course. Thanks, Lorenzo
