On Mon, Sep 26, 2022 at 10:01:55PM +0800, Zhuo Chen wrote:

On 9/23/22 5:08 AM, Bjorn Helgaas wrote:

quoted

On Fri, Sep 02, 2022 at 02:16:33AM +0800, Zhuo Chen wrote:

quoted

When state is pci_channel_io_frozen in pcie_do_recovery(),
the severity is fatal and fatal status should be cleared.
So we add pci_aer_clear_fatal_status().

Seems sensible to me.  Did you find this by code inspection or by
debugging a problem?  If the latter, it would be nice to mention the
symptoms of the problem in the commit log.

I found this by code inspection so I may not enumerate what kind of problems
this code will cause.

quoted

quoted

Since pcie_aer_is_native() in pci_aer_clear_fatal_status()
and pci_aer_clear_nonfatal_status() contains the function of
'if (host->native_aer || pcie_ports_native)', so we move them
out of it.

Wrap commit log to fill 75 columns.

quoted

Signed-off-by: Zhuo Chen <redacted>
---
  drivers/pci/pcie/err.c | 8 ++++++--
  1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 0c5a143025af..e0a8ade4c3fe 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c

@@ -243,10 +243,14 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev,
  	 * it is responsible for clearing this status.  In that case, the
  	 * signaling device may not even be visible to the OS.
  	 */
-	if (host->native_aer || pcie_ports_native) {
+	if (host->native_aer || pcie_ports_native)
  		pcie_clear_device_status(dev);

pcie_clear_device_status() doesn't check for pcie_aer_is_native()
internally, but after 068c29a248b6 ("PCI/ERR: Clear PCIe Device Status
errors only if OS owns AER") and aa344bc8b727 ("PCI/ERR: Clear AER
status only when we control AER"), both callers check before calling
it.

I think we should move the check inside pcie_clear_device_status().
That could be a separate preliminary patch.

There are a couple other places (aer_root_reset() and
get_port_device_capability()) that do the same check and could be
changed to use pcie_aer_is_native() instead.  That could be another
preliminary patch.

Good suggestion. But I have only one doubt. In aer_root_reset(), if we use
"if (pcie_aer_is_native(dev) && aer)", when dev->aer_cap
is NULL and root->aer_cap is not NULL, pcie_aer_is_native() will return
false. It's different from just using "(host->native_aer ||
pcie_ports_native)".
Or if we can use "if (pcie_aer_is_native(root))", at this time a NULL
pointer check should be added in pcie_aer_is_native() because root may be
NULL.

Good point.  In aer_root_reset(), we're updating Root Port registers,
so I think they should look like:

  if (pcie_aer_is_native(root) && aer) {
    ...
  }

Does that seem safe and equivalent to you?

Bjorn