Re: [PATCH v1 3/3] PCI: qcom: Add support for detecting controller level PCIe errors

[Bjorn Helgaas <helgaas@kernel.org>]

On Wed, Feb 21, 2024 at 12:50:17PM -0600, Bjorn Helgaas wrote:
> On Wed, Feb 21, 2024 at 07:34:04PM +0530, root wrote:
> > From: Nitesh Gupta <nitegupt@quicinc.com>
> > 
> > Synopsys Controllers provide capabilities to detect various controller
> > level errors. These can range from controller interface error to random
> > PCIe configuration errors. This patch intends to add support to detect
> > these errors and report it to userspace entity via sysfs, which can take
> > appropriate actions to mitigate the errors.

> > +static void qcom_pcie_enable_error_reporting_2_7_0(struct qcom_pcie *pcie)
> > +{
> > + ...
> 
> > +	val = readl(pci->dbi_base + DBI_DEVICE_CONTROL_DEVICE_STATUS);
> > +	val |= (PCIE_CAP_CORR_ERR_REPORT_EN | PCIE_CAP_NON_FATAL_ERR_REPORT_EN |
> > +			PCIE_CAP_FATAL_ERR_REPORT_EN | PCIE_CAP_UNSUPPORT_REQ_REP_EN);
> > +	writel(val, pci->dbi_base + DBI_DEVICE_CONTROL_DEVICE_STATUS);
> 
> Is there any way to split the AER part (specified by the PCIe spec)
> from the qcom-specific (or dwc-specific) part?  This looks an awful
> lot like pci_enable_pcie_error_reporting(), and we should do this in
> the PCI core in a generic way if possible.
> 
> > +	val = readl(pci->dbi_base + DBI_ROOT_CONTROL_ROOT_CAPABILITIES_REG);
> > +	val |= (PCIE_CAP_SYS_ERR_ON_CORR_ERR_EN | PCIE_CAP_SYS_ERR_ON_NON_FATAL_ERR_EN |
> > +			PCIE_CAP_SYS_ERR_ON_FATAL_ERR_EN);
> > +	writel(val, pci->dbi_base + DBI_ROOT_CONTROL_ROOT_CAPABILITIES_REG);

More to the point: why do we need to do this in the qcom driver at
all?  Why is pci_enable_pcie_error_reporting() not enough?

Bjorn