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(-) -- 2.19.1
