[PATCH v16 2/9] pci-error-recovery: Add AER_FATAL handling

Oza Pawandeep
2018-05-11T10:43:21Z

It adds description on AER_FATAL error handling.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>

diff --git a/Documentation/PCI/pci-error-recovery.txt b/Documentation/PCI/pci-error-recovery.txt
index 0b6bb3e..688b691 100644
--- a/Documentation/PCI/pci-error-recovery.txt
+++ b/Documentation/PCI/pci-error-recovery.txt
@@ -110,7 +110,7 @@ The actual steps taken by a platform to recover from a PCI error
event will be platform-dependent, but will follow the general
sequence described below.

-STEP 0: Error Event
+STEP 0: Error Event: ERR_NONFATAL
-------------------
A PCI bus error is detected by the PCI hardware. On powerpc, the slot
is isolated, in that all I/O is blocked: all reads return 0xffffffff,
@@ -228,13 +228,7 @@ proceeds to either STEP3 (Link Reset) or to STEP 5 (Resume Operations).
If any driver returned PCI_ERS_RESULT_NEED_RESET, then the platform
proceeds to STEP 4 (Slot Reset)

-STEP 3: Link Reset
-------------------
-The platform resets the link. This is a PCI-Express specific step
-and is done whenever a fatal error has been detected that can be
-"solved" by resetting the link.
-
-STEP 4: Slot Reset
+STEP 3: Slot Reset
------------------

In response to a return value of PCI_ERS_RESULT_NEED_RESET, the
@@ -320,7 +314,7 @@ Failure).
>>> However, it probably should.

-STEP 5: Resume Operations
+STEP 4: Resume Operations
-------------------------
The platform will call the resume() callback on all affected device
drivers if all drivers on the segment have returned
@@ -332,7 +326,7 @@ a result code.
At this point, if a new error happens, the platform will restart
a new error recovery sequence.

-STEP 6: Permanent Failure
+STEP 5: Permanent Failure
-------------------------
A "permanent failure" has occurred, and the platform cannot recover
the device. The platform will call error_detected() with a
@@ -355,6 +349,27 @@ errors. See the discussion in powerpc/eeh-pci-error-recovery.txt
for additional detail on real-life experience of the causes of
software errors.

+STEP 0: Error Event: ERR_FATAL
+-------------------
+PCI bus error is detected by the PCI hardware. On powerpc, the slot is
+isolated, in that all I/O is blocked: all reads return 0xffffffff, all
+writes are ignored.
+
+STEP 1: Remove devices
+--------------------
+Platform removes the devices depending on the error agent, it could be
+this port for all subordinates or upstream component (likely downstream
+port)
+
+STEP 2: Reset link
+--------------------
+The platform resets the link. This is a PCI-Express specific step and is
+done whenever a fatal error has been detected that can be "solved" by
+resetting the link.
+
+STEP 3: Re-enumerate the devices
+--------------------
+Initiates the re-enumeration.

Conclusion; General Remarks
---------------------------
--
2.7.4