From fce5423e4f431c71933d6c1f850b540a314aa6ee Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 13 Nov 2018 22:57:33 +0000 Subject: [PATCH] PCI: dwc: Take lock when ACKing an interrupt 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/20181113225734.8026-1-marc.zyngier@arm.com/ Tested-by: Niklas Cassel Tested-by: Gustavo Pimentel Tested-by: Stanimir Varbanov Signed-off-by: Marc Zyngier [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi Cc: stable@vger.kernel.org --- drivers/pci/controller/dwc/pcie-designware-host.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 0f81b71..610a5e0 100644 --- 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_data *d) { 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 = { -- 2.7.4