> Subject: Re: [PATCH v2] PCI/AER: Enable SERR# forwarding in non ACPI flow
>
> On 2018-08-09 20:27, Bharat Kumar Gogada wrote:
> > As per Figure 6-3 in PCIe r4.0, sec 6.2.6, ERR_ messages will be
> > forwarded from the secondary interface to the primary interface, if
> > the SERR# Enable bit in the Bridge Control register is set.
> > Currently PCI_BRIDGE_CTL_SERR is being enabled only in ACPI flow.
> > This patch enables PCI_BRIDGE_CTL_SERR for Type-1 PCI device.
> >
> > Signed-off-by: Bharat Kumar Gogada <bharat.kumar.gog...@xilinx.com>
> > ---
> > drivers/pci/pcie/aer.c | 23 +++++++++++++++++++++++
> > 1 files changed, 23 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c index
> > a2e8838..4fb0d24 100644
> > --- a/drivers/pci/pcie/aer.c
> > +++ b/drivers/pci/pcie/aer.c
> > @@ -343,6 +343,20 @@ int pci_enable_pcie_error_reporting(struct
> > pci_dev
> > *dev)
> > if (!dev->aer_cap)
> > return -EIO;
> >
> > + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
> > + u16 control;
> > +
> > + /*
> > + * A Type-1 PCI bridge will not forward ERR_ messages
> coming
> > + * from an endpoint if SERR# forwarding is not enabled.
> > + */
> > + pci_read_config_word(dev, PCI_BRIDGE_CONTROL,
> &control);
> > + if (!(control & PCI_BRIDGE_CTL_SERR)) {
> > + control |= PCI_BRIDGE_CTL_SERR;
> > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL,
> control);
> > + }
> > + }
> > +
> > return pcie_capability_set_word(dev, PCI_EXP_DEVCTL,
> > PCI_EXP_AER_FLAGS); }
> > EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
> > @@ -352,6 +366,15 @@ int pci_disable_pcie_error_reporting(struct
> > pci_dev *dev)
> > if (pcie_aer_get_firmware_first(dev))
> > return -EIO;
> >
> > + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
> > + u16 control;
> > +
> > + /* Clear SERR Forwarding */
> > + pci_read_config_word(dev, PCI_BRIDGE_CONTROL,
> &control);
> > + control &= ~PCI_BRIDGE_CTL_SERR;
> > + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control);
> > + }
> > +
> > return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
> > PCI_EXP_AER_FLAGS);
> > }
>
>
> Hi Bjorn,
>
> I made some comments on patchv1., same I am putting it across here.
>
> what about hot-plug case ?
> should not aer_init() call pci_enable_pcie_error_reporting() for all the
> downstream pci_dev ?
> and remove all the calls from drivers..
> aer_init will be called for each device (pci_dev) while pciehp does re-
> enumeration.
> so probable we might want to call pci_enable_pcie_error_reporting() but
> that dictates the design where AER framework is taking decision to enable
> error reporting on behalf of drivers as well.
> but thats fine I think, if drivers do not want to participate then they have
> to
> call pci_disable_pcie_error_reporting explicitly.
> does this make sense ?
>
Hi Bjorn,
Can you please comment on this.
Bharat
