On Tue, Nov 13, 2018 at 10:57:34PM +0000, Marc Zyngier wrote:
> 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.
>
> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> ---
> drivers/pci/controller/dwc/pcie-designware-host.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 0a76948ed49e..f06e67c60593 100644
> --- 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 pcie_port *pp)
> (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 irq_data *data)
>
> 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);
>
Tested-by: Niklas Cassel <niklas.cassel@xxxxxxxxxx>
