4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier marc.zyngier@arm.com
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/20181113225734.8026-1-marc.zyngier@arm.com... Tested-by: Niklas Cassel niklas.cassel@linaro.org Tested-by: Gustavo Pimentel gustavo.pimentel@synopsys.com Tested-by: Stanimir Varbanov svarbanov@mm-sol.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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 = {