[U-Boot] [PATCH V2] test/py: ignore console read exceptions after test failure

[Heinrich Schuchardt]

On 09/21/2018 12:55 AM, Stephen Warren wrote:
> From: Stephen Warren <swarren at nvidia.com>
> 
> After a test has failed, test/py drains the U-Boot console log to ensure
> that any relevant output is captured. At this point, we don't care about
> detecting any additional errors, since the test is already known to have
> failed, and U-Boot will be restarted. To ensure that the test cleanup code
> is not interrupted, and can correctly terminate the log sections for the
> failed test, ignore any exception that occurs while reading the U-Boot
> console output during this limited period of time.
> 
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> ---
> v2:
> * Combine the two except cases into one, since one was a superset of the
>   other.
> * Fix TAB-vs-spaces issue in identation.
> ---
>  test/py/u_boot_console_base.py | 12 +++++++++++-
>  1 file changed, 11 insertions(+), 1 deletion(-)
> 
> diff --git a/test/py/u_boot_console_base.py b/test/py/u_boot_console_base.py
> index a14bad6e8c50..326b2ac51fbf 100644
> --- a/test/py/u_boot_console_base.py
> +++ b/test/py/u_boot_console_base.py
> @@ -304,7 +304,17 @@ class ConsoleBase(object):
>              # Wait for something U-Boot will likely never send. This will
>              # cause the console output to be read and logged.
>              self.p.expect(['This should never match U-Boot output'])
> -        except u_boot_spawn.Timeout:
> +        except:
> +            # We expect a timeout, since U-Boot won't print what we waited
> +            # for. Squash it when it happens.
> +            #
> +            # Squash any other exception too. This function is only used to
> +            # drain (and log) the U-Boot console output after a failed test.
> +            # The U-Boot process will be restarted, or target board reset, once
> +            # this function returns. So, we don't care about detecting any
> +            # additional errors, so they're squashed so that the rest of the
> +            # post-test-failure cleanup code can continue operation, and
> +            # correctly terminate any log sections, etc.
>              pass
>          finally:
>              self.p.timeout = orig_timeout
> 
This patch only covers this single usage of the expect(). Expect() is
called from many test cases directly. In all these cases we still will
not catch OSErrror if the U-Boot binary terminates breaking the pipes.

That is why in my patch I put the except statement into the except()
method itself.

What problem do you see in catching the exception where it is arising?

Best regards

Heinrich