diff options
| author | Jani Nikula <jani.nikula@intel.com> | 2024-03-08 19:03:39 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-03 16:28:32 +0300 |
| commit | 12bbe2c25cdb571190d523fd814e7696964a84d9 (patch) | |
| tree | c32b4ee553e1848f33dd3b04927cb779babf3855 | |
| parent | a64ab862e84e3e698cd351a87cdb504c7fc575ca (diff) | |
| download | linux-12bbe2c25cdb571190d523fd814e7696964a84d9.tar.xz | |
drm/probe-helper: warn about negative .get_modes()
[ Upstream commit 7af03e688792293ba33149fb8df619a8dff90e80 ]
The .get_modes() callback is supposed to return the number of modes,
never a negative error code. If a negative value is returned, it'll just
be interpreted as a negative count, and added to previous calculations.
Document the rules, but handle the negative values gracefully with an
error message.
Cc: stable@vger.kernel.org
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/50208c866facc33226a3c77b82bb96aeef8ef310.1709913674.git.jani.nikula@intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/drm_probe_helper.c | 7 | ||||
| -rw-r--r-- | include/drm/drm_modeset_helper_vtables.h | 3 |
2 files changed, 9 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 3f479483d7d8..15ed974bcb98 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -419,6 +419,13 @@ static int drm_helper_probe_get_modes(struct drm_connector *connector) count = connector_funcs->get_modes(connector); + /* The .get_modes() callback should not return negative values. */ + if (count < 0) { + drm_err(connector->dev, ".get_modes() returned %pe\n", + ERR_PTR(count)); + count = 0; + } + /* * Fallback for when DDC probe failed in drm_get_edid() and thus skipped * override/firmware EDID. diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h index e3c3ac615909..159213786e6e 100644 --- a/include/drm/drm_modeset_helper_vtables.h +++ b/include/drm/drm_modeset_helper_vtables.h @@ -898,7 +898,8 @@ struct drm_connector_helper_funcs { * * RETURNS: * - * The number of modes added by calling drm_mode_probed_add(). + * The number of modes added by calling drm_mode_probed_add(). Return 0 + * on failures (no modes) instead of negative error codes. */ int (*get_modes)(struct drm_connector *connector); |