Hi, On Tue, Jun 13, 2023 at 11:41 AM Stephen Boyd <swboyd@xxxxxxxxxxxx> wrote: > > Quoting Douglas Anderson (2023-06-13 06:58:13) > > Memory for the "struct device" for any given device isn't supposed to > > be released until the device's release() is called. This is important > > because someone might be holding a kobject reference to the "struct > > device" and might try to access one of its members even after any > > other cleanup/uninitialization has happened. > > > > Code analysis of ti-sn65dsi86 shows that this isn't quite right. When > > the code was written, it was believed that we could rely on the fact > > that the child devices would all be freed before the parent devices > > and thus we didn't need to worry about a release() function. While I > > still believe that the parent's "struct device" is guaranteed to > > outlive the child's "struct device" (because the child holds a kobject > > reference to the parent), the parent's "devm" allocated memory is a > > different story. That appears to be freed much earlier. > > > > Let's make this better for ti-sn65dsi86 by allocating each auxiliary > > with kzalloc and then free that memory in the release(). > > > > Fixes: bf73537f411b ("drm/bridge: ti-sn65dsi86: Break GPIO and MIPI-to-eDP bridge into sub-drivers") > > Suggested-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> > > Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> > > --- > > Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx> Pushed to drm-misc-fixes: 7aa83fbd712a drm/bridge: ti-sn65dsi86: Fix auxiliary bus lifetime