Messages in this thread | | | Date | Mon, 10 Sep 2018 11:40:02 +0530 | From | poza@codeauro ... | Subject | Re: [PATCH v2] PCI/AER: Enable SERR# forwarding in non ACPI flow |
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On 2018-09-06 01:40, Bjorn Helgaas wrote: > On Thu, Aug 09, 2018 at 08:41:27PM +0530, poza@codeaurora.org wrote: >> 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.gogada@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 ? > > I just replied to the original patch; sorry, I forgot to add you to > the cc list. Bharat, when people respond to your v<N> patch, can you > please add them (and anybody else *they* added) to the cc list when > you post your v<N+1> patch? > > If we set PCI_BRIDGE_CTL_SERR in the pci_configure_device() path, > would that address your comments?
yes, that should do.
> > There's still a separate question of where and how we should configure > the error bits in PCI_EXP_DEVCTL (currently done in > pci_enable_pcie_error_reporting()). > > Bjorn
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