| Message ID | 79f559b72d8c493940417304e222a4b04dfa19c4.1709913674.git.jani.nikula@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm: fix .get_modes() return values | expand |
On 3/8/2024 8:03 AM, Jani Nikula wrote: > None of the callers of drm_panel_get_modes() expect it to return > negative error codes. Either they propagate the return value in their > struct drm_connector_helper_funcs .get_modes() hook (which is also not > supposed to return negative codes), or add it to other counts leading to > bogus values. > > On the other hand, many of the struct drm_panel_funcs .get_modes() hooks > do return negative error codes, so handle them gracefully instead of > propagating further. > > Return 0 for no modes, whatever the reason. > > Cc: Neil Armstrong <neil.armstrong@linaro.org> > Cc: Jessica Zhang <quic_jesszhan@quicinc.com> > Cc: Sam Ravnborg <sam@ravnborg.org> > Cc: stable@vger.kernel.org > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/drm_panel.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c > index e814020bbcd3..cfbe020de54e 100644 > --- a/drivers/gpu/drm/drm_panel.c > +++ b/drivers/gpu/drm/drm_panel.c > @@ -274,19 +274,24 @@ EXPORT_SYMBOL(drm_panel_disable); > * The modes probed from the panel are automatically added to the connector > * that the panel is attached to. > * > - * Return: The number of modes available from the panel on success or a > - * negative error code on failure. > + * Return: The number of modes available from the panel on success, or 0 on > + * failure (no modes). > */ > int drm_panel_get_modes(struct drm_panel *panel, > struct drm_connector *connector) > { > if (!panel) > - return -EINVAL; > + return 0; > > - if (panel->funcs && panel->funcs->get_modes) > - return panel->funcs->get_modes(panel, connector); > + if (panel->funcs && panel->funcs->get_modes) { > + int num; > > - return -EOPNOTSUPP; > + num = panel->funcs->get_modes(panel, connector); > + if (num > 0) > + return num; Hi Jani, The change LGTM: Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com> Thanks, Jessica Zhang > + } > + > + return 0; > } > EXPORT_SYMBOL(drm_panel_get_modes); > > -- > 2.39.2 >
On 08/03/2024 17:03, Jani Nikula wrote: > None of the callers of drm_panel_get_modes() expect it to return > negative error codes. Either they propagate the return value in their > struct drm_connector_helper_funcs .get_modes() hook (which is also not > supposed to return negative codes), or add it to other counts leading to > bogus values. > > On the other hand, many of the struct drm_panel_funcs .get_modes() hooks > do return negative error codes, so handle them gracefully instead of > propagating further. > > Return 0 for no modes, whatever the reason. > > Cc: Neil Armstrong <neil.armstrong@linaro.org> > Cc: Jessica Zhang <quic_jesszhan@quicinc.com> > Cc: Sam Ravnborg <sam@ravnborg.org> > Cc: stable@vger.kernel.org > Signed-off-by: Jani Nikula <jani.nikula@intel.com> > --- > drivers/gpu/drm/drm_panel.c | 17 +++++++++++------ > 1 file changed, 11 insertions(+), 6 deletions(-) > > diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c > index e814020bbcd3..cfbe020de54e 100644 > --- a/drivers/gpu/drm/drm_panel.c > +++ b/drivers/gpu/drm/drm_panel.c > @@ -274,19 +274,24 @@ EXPORT_SYMBOL(drm_panel_disable); > * The modes probed from the panel are automatically added to the connector > * that the panel is attached to. > * > - * Return: The number of modes available from the panel on success or a > - * negative error code on failure. > + * Return: The number of modes available from the panel on success, or 0 on > + * failure (no modes). > */ > int drm_panel_get_modes(struct drm_panel *panel, > struct drm_connector *connector) > { > if (!panel) > - return -EINVAL; > + return 0; > > - if (panel->funcs && panel->funcs->get_modes) > - return panel->funcs->get_modes(panel, connector); > + if (panel->funcs && panel->funcs->get_modes) { > + int num; > > - return -EOPNOTSUPP; > + num = panel->funcs->get_modes(panel, connector); > + if (num > 0) > + return num; > + } > + > + return 0; > } > EXPORT_SYMBOL(drm_panel_get_modes); > Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c index e814020bbcd3..cfbe020de54e 100644 --- a/drivers/gpu/drm/drm_panel.c +++ b/drivers/gpu/drm/drm_panel.c @@ -274,19 +274,24 @@ EXPORT_SYMBOL(drm_panel_disable); * The modes probed from the panel are automatically added to the connector * that the panel is attached to. * - * Return: The number of modes available from the panel on success or a - * negative error code on failure. + * Return: The number of modes available from the panel on success, or 0 on + * failure (no modes). */ int drm_panel_get_modes(struct drm_panel *panel, struct drm_connector *connector) { if (!panel) - return -EINVAL; + return 0; - if (panel->funcs && panel->funcs->get_modes) - return panel->funcs->get_modes(panel, connector); + if (panel->funcs && panel->funcs->get_modes) { + int num; - return -EOPNOTSUPP; + num = panel->funcs->get_modes(panel, connector); + if (num > 0) + return num; + } + + return 0; } EXPORT_SYMBOL(drm_panel_get_modes);
None of the callers of drm_panel_get_modes() expect it to return negative error codes. Either they propagate the return value in their struct drm_connector_helper_funcs .get_modes() hook (which is also not supposed to return negative codes), or add it to other counts leading to bogus values. On the other hand, many of the struct drm_panel_funcs .get_modes() hooks do return negative error codes, so handle them gracefully instead of propagating further. Return 0 for no modes, whatever the reason. Cc: Neil Armstrong <neil.armstrong@linaro.org> Cc: Jessica Zhang <quic_jesszhan@quicinc.com> Cc: Sam Ravnborg <sam@ravnborg.org> Cc: stable@vger.kernel.org Signed-off-by: Jani Nikula <jani.nikula@intel.com> --- drivers/gpu/drm/drm_panel.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)