Hi,
On 6/17/20 2:31 AM, Jonathan Cameron wrote:
On Tue, 16 Jun 2020 11:00:32 -0700
"Kuppuswamy, Sathyanarayanan" <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> wrote:
Hi Jonathan,
On 6/16/20 10:47 AM, Bjorn Helgaas wrote:
[+cc Sathy]
On Fri, May 22, 2020 at 01:31:33AM +0800, Jonathan Cameron wrote:
pci_aer_clear_device_status() currently resets the device status even when
firmware first handling is going on. In particular it resets it on the
root port.
This has been discussed previously
https://lore.kernel.org/patchwork/patch/427375/.
pci_aer_clear_device_status() is only used by handle_error_source(). And
I don't think handle_error_source() is called in FF mode. Can you
give more details on this issue ?
It's called in pcie_do_recovery
https://elixir.bootlin.com/linux/latest/source/drivers/pci/pcie/err.c#L200
Which is called from both handle_error_source and aer_recover_work_func.
indirectly called from ghes_handle_aer / ghes_do_proc
This particular flow will only happen (I think) on hardware reduced ACPI systems.
Ok. Makes sense.
Jonathan
I don't think this reference is really pertinent, is it? That patch
to b2c8881da764 changes pci_cleanup_aer_uncorrect_error_status() so it
doesn't clear PCI_ERR_UNCOR_STATUS in "firmware-first" mode.
But your patch only affects PCI_EXP_DEVSTA, not PCI_ERR_UNCOR_STATUS.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/pci/pcie/aer.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index f4274d301235..43e78b97ace6 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -373,6 +373,9 @@ void pci_aer_clear_device_status(struct pci_dev *dev)
{
u16 sta;
+ if (pcie_aer_get_firmware_first(dev))
use if (!pcie_aer_is_native(dev))
+ return;
This needs to be adjusted because pcie_aer_get_firmware_first() no
longer exists after 708b20003624 ("PCI/AER: Remove HEST/FIRMWARE_FIRST
parsing for AER ownership").
This will use the _OSC AER ownership bit to gate clearing of the
status bits in the PCIe capability (not the AER capability).
I think that's the right thing to do, but it's certainly not obvious
from the _OSC description in the PCI Firmware Spec r3.2. I think we
need a pointer to the ECN that clarifies this, i.e., sec 4.5.1 of:
System Firmware Intermediary (SFI) _OSC and DPC Updates ECN, Feb 24,
2020, affecting PCI Firmware Specification, Rev. 3.2
https://members.pcisig.com/wg/PCI-SIG/document/14076
pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta);
pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta);
}
--
2.19.1
--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer
