4.20-stable review patch. If anyone has any objections, please let me know.
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From: Marc Zyngier marc.zyngier@arm.com
commit 3f7bb2ec20ce07c02b2002349d256c91a463fcc5 upstream.
The write to the status register is really an ACK for the HW, and should be treated as such by the driver. Let's move it to the irq_ack() callback, which will prevent people from moving it around in order to paper over other bugs.
Fixes: 8c934095fa2f ("PCI: dwc: Clear MSI interrupt status after it is handled, not before") 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... Reported-by: Trent Piepho tpiepho@impinj.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 | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-)
--- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -99,9 +99,6 @@ irqreturn_t dw_handle_msi_irq(struct pci (i * MAX_MSI_IRQS_PER_CTRL) + pos); generic_handle_irq(irq); - dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + - (i * MSI_REG_CTRL_BLOCK_SIZE), - 4, 1 << pos); pos++; } } @@ -200,14 +197,18 @@ static void dw_pci_bottom_unmask(struct
static void dw_pci_bottom_ack(struct irq_data *d) { - struct msi_desc *msi = irq_data_get_msi_desc(d); - struct pcie_port *pp; + struct pcie_port *pp = irq_data_get_irq_chip_data(d); + unsigned int res, bit, ctrl; unsigned long flags;
- pp = msi_desc_to_pci_sysdata(msi); + ctrl = d->hwirq / MAX_MSI_IRQS_PER_CTRL; + res = ctrl * MSI_REG_CTRL_BLOCK_SIZE; + bit = d->hwirq % MAX_MSI_IRQS_PER_CTRL;
raw_spin_lock_irqsave(&pp->lock, flags);
+ dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_STATUS + res, 4, 1 << bit); + if (pp->ops->msi_irq_ack) pp->ops->msi_irq_ack(d->hwirq, pp);