4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Marc Zyngier <marc.zyngier@xxxxxxx>
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@xxxxxxx/
Tested-by: Niklas Cassel <niklas.cassel@xxxxxxxxxx>
Tested-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
Tested-by: Stanimir Varbanov <svarbanov@xxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
[lorenzo.pieralisi@xxxxxxx: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 = {
