[PATCH] selftests/powerpc: Squash spurious errors due to device removal

2020-07-26 Thread Oliver O'Halloran
For drivers that don't have the error handling callbacks we implement
recovery by removing the device and re-probing it. This causes the sysfs
directory for the PCI device to be removed which causes the following
spurious error to be printed when checking the PE state:

Breaking 0005:03:00.0...
./eeh-basic.sh: line 13: can't open 
/sys/bus/pci/devices/0005:03:00.0/eeh_pe_state: no such file
0005:03:00.0, waited 0/60
0005:03:00.0, waited 1/60
0005:03:00.0, waited 2/60
0005:03:00.0, waited 3/60
0005:03:00.0, waited 4/60
0005:03:00.0, waited 5/60
0005:03:00.0, waited 6/60
0005:03:00.0, waited 7/60
0005:03:00.0, Recovered after 8 seconds

We currently try to avoid this by checking if the PE state file exists
before reading from it. This is however inherently racy so re-work the
state checking so that we only read from the file once, and we squash any
errors that occur while reading.

Fixes: 85d86c8aa52e ("selftests/powerpc: Add basic EEH selftest")
Signed-off-by: Oliver O'Halloran 
---
 tools/testing/selftests/powerpc/eeh/eeh-functions.sh | 11 ---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/powerpc/eeh/eeh-functions.sh 
b/tools/testing/selftests/powerpc/eeh/eeh-functions.sh
index f52ed92b53e7..00dc32c0ed75 100755
--- a/tools/testing/selftests/powerpc/eeh/eeh-functions.sh
+++ b/tools/testing/selftests/powerpc/eeh/eeh-functions.sh
@@ -5,12 +5,17 @@ pe_ok() {
local dev="$1"
local path="/sys/bus/pci/devices/$dev/eeh_pe_state"
 
-   if ! [ -e "$path" ] ; then
+   # if a driver doesn't support the error handling callbacks then the
+   # device is recovered by removing and re-probing it. This causes the
+   # sysfs directory to disappear so read the PE state once and squash
+   # any potential error messages
+   local eeh_state="$(cat $path 2>/dev/null)"
+   if [ -z "$eeh_state" ]; then
return 1;
fi
 
-   local fw_state="$(cut -d' ' -f1 < $path)"
-   local sw_state="$(cut -d' ' -f2 < $path)"
+   local fw_state="$(echo $eeh_state | cut -d' ' -f1)"
+   local sw_state="$(echo $eeh_state | cut -d' ' -f2)"
 
# If EEH_PE_ISOLATED or EEH_PE_RECOVERING are set then the PE is in an
# error state or being recovered. Either way, not ok.
-- 
2.26.2



Re: [PATCH] selftests/powerpc: Squash spurious errors due to device removal

2020-07-30 Thread Michael Ellerman
On Mon, 27 Jul 2020 11:01:27 +1000, Oliver O'Halloran wrote:
> For drivers that don't have the error handling callbacks we implement
> recovery by removing the device and re-probing it. This causes the sysfs
> directory for the PCI device to be removed which causes the following
> spurious error to be printed when checking the PE state:
> 
> Breaking 0005:03:00.0...
> ./eeh-basic.sh: line 13: can't open 
> /sys/bus/pci/devices/0005:03:00.0/eeh_pe_state: no such file
> 0005:03:00.0, waited 0/60
> 0005:03:00.0, waited 1/60
> 0005:03:00.0, waited 2/60
> 0005:03:00.0, waited 3/60
> 0005:03:00.0, waited 4/60
> 0005:03:00.0, waited 5/60
> 0005:03:00.0, waited 6/60
> 0005:03:00.0, waited 7/60
> 0005:03:00.0, Recovered after 8 seconds
> 
> [...]

Applied to powerpc/next.

[1/1] selftests/powerpc: Squash spurious errors due to device removal
  https://git.kernel.org/powerpc/c/5f8cf6475828b600ff6d000e580c961ac839cc61

cheers