PCI/ERR: Handle fatal error recovery

We don't need to be paranoid about the topology changing while handling an
error.  If the device has changed in a hotplug capable slot, we can rely on
the presence detection handling to react to a changing topology.

Restore the fatal error handling behavior that existed before merging DPC
with AER with 7e9084b36740 ("PCI/AER: Handle ERR_FATAL with removal and
re-enumeration of devices").

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>

1 files changed, 10 insertions, 25 deletions

diff --git a/Documentation/PCI/pci-error-recovery.txt b/Documentation/PCI/pci-error-recovery.txt
index 688b69121e82..0b6bb3ef449e 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: ERR_NONFATAL
+STEP 0: Error Event
 -------------------
 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,
@@ -228,7 +228,13 @@ 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: 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
 ------------------
 
 In response to a return value of PCI_ERS_RESULT_NEED_RESET, the
@@ -314,7 +320,7 @@ Failure).
 >>> However, it probably should.
 
 
-STEP 4: Resume Operations
+STEP 5: Resume Operations
 -------------------------
 The platform will call the resume() callback on all affected device
 drivers if all drivers on the segment have returned
@@ -326,7 +332,7 @@ a result code.
 At this point, if a new error happens, the platform will restart
 a new error recovery sequence.
 
-STEP 5: Permanent Failure
+STEP 6: Permanent Failure
 -------------------------
 A "permanent failure" has occurred, and the platform cannot recover
 the device.  The platform will call error_detected() with a
@@ -349,27 +355,6 @@ 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
 ---------------------------