[PATCH i-g-t] tests/intel/kms_frontbuffer_tracking: Invalidate cached stuff

[Gustavo Sousa]

+cc Ravi.

Quoting Gustavo Sousa (2024-02-09 10:55:27-03:00)
>The test pipe-fbc-rte updates the primary mode parameters for each valid
>dynamic test case. Because of that, we might endup with invalid cached
>data due to differences between the initial state of prim_mode_params
>defined from the beginning of the test program and the possibly changed
>state after pipe-fbc-rte.
>
>As an example, in a specific environment, the command
>
>  ./build/tests/kms_frontbuffer_tracking \
>      --run-subtest pipe-fbc-rte,fbc-1p-primscrn-pri-indfb-draw-mmap-wc
>
>would result in fbc-1p-primscrn-pri-indfb-draw-mmap-wc failing because
>it would try to read CRC from pipe B while the test was being actually
>done in pipe A.
>
>Another potential issue worth noting is that even pipe-fbc-rte could
>similarly fail if the set of dynamic subtests spanned across multiple
>pipes.
>
>Let's fix that by making sure that cached stuff that would depend on the
>primary mode parameters gets properly invalidated when prim_mode_params
>is the target of init_mode_params(). This should fix the issues
>mentioned above and also future-proof the code for any future test that
>would need to modify the prim_mode_params.
>
>Signed-off-by: Gustavo Sousa <gustavo.sousa at intel.com>
>---
> tests/intel/kms_frontbuffer_tracking.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
>diff --git a/tests/intel/kms_frontbuffer_tracking.c b/tests/intel/kms_frontbuffer_tracking.c
>index 912cca3f8d45..17f74990979e 100644
>--- a/tests/intel/kms_frontbuffer_tracking.c
>+++ b/tests/intel/kms_frontbuffer_tracking.c
>@@ -1484,6 +1484,7 @@ static drmModeModeInfo *connector_get_mode(igt_output_t *output)
> static void init_mode_params(struct modeset_params *params,
>                              igt_output_t *output, enum pipe pipe)
> {
>+        int i;
>         drmModeModeInfo *mode;
> 
>         igt_output_override_mode(output, NULL);
>@@ -1515,6 +1516,18 @@ static void init_mode_params(struct modeset_params *params,
>         params->sprite.w = 64;
>         params->sprite.h = 64;
> 
>+        /* If we endup changing the primary mode parameters, we need to
>+         * invalidate any existing cached stuff from a previous configuration. */
>+        if (params == &prim_mode_params) {
>+                if (pipe_crc) {
>+                        igt_pipe_crc_free(pipe_crc);
>+                        pipe_crc = NULL;
>+                }
>+
>+                for (i = 0; i < FORMAT_COUNT; i++)
>+                        blue_crcs[i].initialized = false;
>+        }
>+
>         free(mode);
> }
> 
>-- 
>2.43.0
>