4.20-stable review patch. If anyone has any objections, please let me know.
------------------ From: Marc Zyngier <[email protected]> commit fce5423e4f431c71933d6c1f850b540a314aa6ee upstream. Bizarrely, there is no lock taken in the irq_ack() helper. This puts the ACK callback provided by a specific platform in a awkward situation where there is no synchronization that would be expected on other callback. Introduce the required lock, giving some level of uniformity among callbacks. Fixes: 7c5925afbc58 ("PCI: dwc: Move MSI IRQs allocation to IRQ domains hierarchical API") Link: https://lore.kernel.org/linux-pci/[email protected]/ Tested-by: Niklas Cassel <[email protected]> Tested-by: Gustavo Pimentel <[email protected]> Tested-by: Stanimir Varbanov <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> [[email protected]: updated commit log] Signed-off-by: Lorenzo Pieralisi <[email protected]> Cc: [email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]> --- drivers/pci/controller/dwc/pcie-designware-host.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -202,11 +202,16 @@ static void dw_pci_bottom_ack(struct irq { struct msi_desc *msi = irq_data_get_msi_desc(d); struct pcie_port *pp; + unsigned long flags; pp = msi_desc_to_pci_sysdata(msi); + raw_spin_lock_irqsave(&pp->lock, flags); + if (pp->ops->msi_irq_ack) pp->ops->msi_irq_ack(d->hwirq, pp); + + raw_spin_unlock_irqrestore(&pp->lock, flags); } static struct irq_chip dw_pci_msi_bottom_irq_chip = {
