On 11/06/2014 02:18 PM, Thierry Reding wrote: > On Thu, Nov 06, 2014 at 12:35:48PM +0100, Andrzej Hajda wrote: >> Exynos DSI driver uses DSI bus attach/detach callbacks to implement >> panel hotplug mechanism. The patch moves panel attachment code >> from .detect callback to DSI bus callbacks. It makes the code >> simpler and more straightforward. >> The patch removes also redundant and lock unprotected dpms_off call >> from unbind code. >> >> Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx> >> --- >> Hi, >> >> This patch simplifies drm part of hotplug mechanism in dsi attach/detach callbacks. >> It also fixes minor bug with unprotected dpms_off call, which is unneccesary anyway. >> >> But the main reason I have looked at this code again is to show that >> we do not need zombie panels, we can kill panels properly if we have hot plug/unplug >> callbacks. And it is quite simple: we just need to take mode_config.mutex locks >> to synchronize dsi callbacks with drm, nothing more. >> It works nicely because of two things: >> - panel callbacks are called always under this lock, >> - callbacks are installed after drmdev creation and deinstalled before drmdev destroy - >> this way we assure drmdev is always present in callbacks. > Again, something like what you propose is going to work only for DSI > devices. What we need is a solution that works for all other types of > panels, too. This is even more important when we consider bridges > because they are less likely to be on a DSI bus. Again:) I say that all we need are just hot plug/unplug callbacks, no zombie panels, no revoke, no try_module_get, etc. Regards Andrzej > > Thierry _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
