On Tue, Jan 15, 2019 at 09:24:37AM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> The patch below does not apply to the 4.14-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
Hello Marc,
You said that you were going to backport this to 4.14, right?
IIRC, you said something about creating a simple dw_pci_bottom_ack()
(since 4.14 lacks a ack() function).
Kind regards,
Niklas
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> From 3f7bb2ec20ce07c02b2002349d256c91a463fcc5 Mon Sep 17 00:00:00 2001
> From: Marc Zyngier <marc.zyngier@xxxxxxx>
> Date: Tue, 13 Nov 2018 22:57:34 +0000
> Subject: [PATCH] PCI: dwc: Move interrupt acking into the proper callback
>
> 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@xxxxxxx/
> Reported-by: Trent Piepho <tpiepho@xxxxxxxxxx>
> 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
>
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 610a5e018d27..0fa9e8fdce66 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);
>
>
