Re: [PATCH v4 2/2] PCI: qcom: Restrict pci transactions after pci suspend

[Johan Hovold <johan@kernel.org>]

On Wed, Jul 06, 2022 at 08:10:25PM +0530, Krishna chaitanya chundru wrote:
> If the endpoint device state is D0 and irq's are not freed, then
> kernel try to mask interrupts in system suspend path by writing
> in to the vector table (for MSIX interrupts) and config space (for MSI's).
> 
> These transactions are initiated in the pm suspend after pcie clocks got
> disabled as part of platform driver pm  suspend call. Due to it, these
> transactions are resulting in un-clocked access and eventually to crashes.
> 
> So added a logic in qcom driver to restrict these unclocked access.
> And updated the logic to check the link state before masking
> or unmasking the interrupts.
> 
> Signed-off-by: Krishna chaitanya chundru <quic_krichai@quicinc.com>
> ---
>  drivers/pci/controller/dwc/pcie-designware-host.c | 14 +++++++--
>  drivers/pci/controller/dwc/pcie-qcom.c            | 36 +++++++++++++++++++++--
>  2 files changed, 46 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
> index 2fa86f3..2a46b40 100644
> --- a/drivers/pci/controller/dwc/pcie-designware-host.c
> +++ b/drivers/pci/controller/dwc/pcie-designware-host.c
> @@ -29,13 +29,23 @@ static void dw_msi_ack_irq(struct irq_data *d)
>  
>  static void dw_msi_mask_irq(struct irq_data *d)
>  {
> -	pci_msi_mask_irq(d);
> +	struct pcie_port *pp = irq_data_get_irq_chip_data(d->parent_data);
> +	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);

When rebasing you'll notice that struct pcie_port has now been renamed:

	60b3c27fb9b9 ("PCI: dwc: Rename struct pcie_port to dw_pcie_rp")

Johan