| Message ID | 20230804140605.RFC.10.I104cdece7324b0c365e552a17f9883414ffaea01@changeid (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/panel: Remove most store/double-check of prepared/enabled state | expand |
On Fri, Aug 04, 2023 at 02:06:13PM -0700, Douglas Anderson wrote: > Now that most panels have been updated not to track/double-check their > prepared/enabled state update the TODO with next steps. > > Signed-off-by: Douglas Anderson <dianders@chromium.org> > --- > > Documentation/gpu/todo.rst | 33 +++++++++++++-------------------- > 1 file changed, 13 insertions(+), 20 deletions(-) > > diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst > index 139980487ccf..c73d9dbebbf4 100644 > --- a/Documentation/gpu/todo.rst > +++ b/Documentation/gpu/todo.rst > @@ -460,26 +460,19 @@ Contact: Thomas Zimmermann <tzimmermann@suse.de> > > Level: Starter > > -Clean up checks for already prepared/enabled in panels > ------------------------------------------------------- > - > -In a whole pile of panel drivers, we have code to make the > -prepare/unprepare/enable/disable callbacks behave as no-ops if they've already > -been called. To get some idea of the duplicated code, try:: > - > - git grep 'if.*>prepared' -- drivers/gpu/drm/panel > - git grep 'if.*>enabled' -- drivers/gpu/drm/panel > - > -In the patch ("drm/panel: Check for already prepared/enabled in drm_panel") > -we've moved this check to the core. Now we can most definitely remove the > -check from the individual panels and save a pile of code. > - > -In adition to removing the check from the individual panels, it is believed > -that even the core shouldn't need this check and that should be considered > -an error if other code ever relies on this check. The check in the core > -currently prints a warning whenever something is relying on this check with > -dev_warn(). After a little while, we likely want to promote this to a > -WARN(1) to help encourage folks not to rely on this behavior. > +Never double prepare/enable/disable/unprepare a panel > +----------------------------------------------------- > + > +As of commit d2aacaf07395 ("drm/panel: Check for already prepared/enabled in > +drm_panel"), we have a check in the drm_panel core to make sure nobody > +double-calls prepare/enable/disable/unprepare. However, that extra double-check > +shouldn't be necessary. The caller should always be matching up calls of > +prepare/unprepare and matching up calls of enable/disable. > + > +Hopefully the warning printed will encourage everyone to fix this. Eventually > +we'll likely want to change this to a WARN_ON and (perhaps) fully remove the > +check. NOTE: even if we remove the double-check, drm_panel core still needs > +to track the enabled/prepared state for its own purposes. Detailing what those purposes are would be nice :) Maxime
diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst index 139980487ccf..c73d9dbebbf4 100644 --- a/Documentation/gpu/todo.rst +++ b/Documentation/gpu/todo.rst @@ -460,26 +460,19 @@ Contact: Thomas Zimmermann <tzimmermann@suse.de> Level: Starter -Clean up checks for already prepared/enabled in panels ------------------------------------------------------- - -In a whole pile of panel drivers, we have code to make the -prepare/unprepare/enable/disable callbacks behave as no-ops if they've already -been called. To get some idea of the duplicated code, try:: - - git grep 'if.*>prepared' -- drivers/gpu/drm/panel - git grep 'if.*>enabled' -- drivers/gpu/drm/panel - -In the patch ("drm/panel: Check for already prepared/enabled in drm_panel") -we've moved this check to the core. Now we can most definitely remove the -check from the individual panels and save a pile of code. - -In adition to removing the check from the individual panels, it is believed -that even the core shouldn't need this check and that should be considered -an error if other code ever relies on this check. The check in the core -currently prints a warning whenever something is relying on this check with -dev_warn(). After a little while, we likely want to promote this to a -WARN(1) to help encourage folks not to rely on this behavior. +Never double prepare/enable/disable/unprepare a panel +----------------------------------------------------- + +As of commit d2aacaf07395 ("drm/panel: Check for already prepared/enabled in +drm_panel"), we have a check in the drm_panel core to make sure nobody +double-calls prepare/enable/disable/unprepare. However, that extra double-check +shouldn't be necessary. The caller should always be matching up calls of +prepare/unprepare and matching up calls of enable/disable. + +Hopefully the warning printed will encourage everyone to fix this. Eventually +we'll likely want to change this to a WARN_ON and (perhaps) fully remove the +check. NOTE: even if we remove the double-check, drm_panel core still needs +to track the enabled/prepared state for its own purposes. Contact: Douglas Anderson <dianders@chromium.org>
Now that most panels have been updated not to track/double-check their prepared/enabled state update the TODO with next steps. Signed-off-by: Douglas Anderson <dianders@chromium.org> --- Documentation/gpu/todo.rst | 33 +++++++++++++-------------------- 1 file changed, 13 insertions(+), 20 deletions(-)