On Wed, Aug 19, 2026 at 03:07:40PM -0400, Mark Yacoub wrote: > Writeback and virtual connectors (e.g. DRM_MODE_CONNECTOR_WRITEBACK and > DRM_MODE_CONNECTOR_VIRTUAL) do not represent physical display sinks and > cannot be modeset using standard CRTC / atomic commit operations without > configuring a writeback output framebuffer (WRITEBACK_FB_ID). > > On drivers such as MSM, writeback connectors (e.g. Virtual-1, Virtual-2) > report connected status with virtual modes. When generic KMS tests iterate > over connected outputs via for_each_connected_output() or during initial > display setup in igt_display_init(), attempting standard modesets on these > connectors causes failures (-EINVAL) before test execution can begin. > > Exclude DRM_MODE_CONNECTOR_WRITEBACK and DRM_MODE_CONNECTOR_VIRTUAL in > igt_output_is_connected() so generic KMS tests only target standard > physical display outputs, while dedicated writeback tests can continue to > iterate all outputs explicitly via for_each_output(). > > Signed-off-by: Mark Yacoub <[email protected]> > --- > lib/igt_kms.h | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/lib/igt_kms.h b/lib/igt_kms.h > index 521a03c01..8d4d14847 100644 > --- a/lib/igt_kms.h > +++ b/lib/igt_kms.h > @@ -668,6 +668,10 @@ static inline bool igt_output_is_connected(igt_output_t > *output) > !output->config.connector->count_modes) > return false; > > + if (output->config.connector->connector_type == > DRM_MODE_CONNECTOR_WRITEBACK || > + output->config.connector->connector_type == > DRM_MODE_CONNECTOR_VIRTUAL) > + return false; > + > if (output->config.connector->connection == DRM_MODE_CONNECTED) > return true; > > -- > 2.55.0.737.g08866a6d13-goog >
This makes a lot of tests (including a lot of kms_*) be skipped on VKMS. Is that correct? Cascardo.
