Hi Dario On Tue, 5 Dec 2023 at 10:54, Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx> wrote: > > The patch fixes the code for finding the next bridge with the > "pre_enable_prev_first" flag set to false. In case this condition is > not verified, i. e. there is no subsequent bridge with the flag set to > false, the whole bridge list is traversed, invalidating the "next" > variable. > > The use of a new iteration variable (i. e. "iter") ensures that the value > of the "next" variable is not invalidated. We already have https://patchwork.freedesktop.org/patch/529288/ that has been reviewed (but not applied) to resolve this. What does this version do differently and why? Dave > Fixes: 4fb912e5e190 ("drm/bridge: Introduce pre_enable_prev_first to alter bridge init order") > Co-developed-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Michael Trimarchi <michael@xxxxxxxxxxxxxxxxxxxx> > Signed-off-by: Dario Binacchi <dario.binacchi@xxxxxxxxxxxxxxxxxxxx> > --- > > (no changes since v1) > > drivers/gpu/drm/drm_bridge.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c > index f66bf4925dd8..2e5781bf192e 100644 > --- a/drivers/gpu/drm/drm_bridge.c > +++ b/drivers/gpu/drm/drm_bridge.c > @@ -662,7 +662,7 @@ void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge, > struct drm_atomic_state *old_state) > { > struct drm_encoder *encoder; > - struct drm_bridge *next, *limit; > + struct drm_bridge *iter, *next, *limit; > > if (!bridge) > return; > @@ -680,14 +680,15 @@ void drm_atomic_bridge_chain_post_disable(struct drm_bridge *bridge, > * was enabled first, so disabled last > */ > limit = next; > + iter = next; > > /* Find the next bridge that has NOT requested > * prev to be enabled first / disabled last > */ > - list_for_each_entry_from(next, &encoder->bridge_chain, > + list_for_each_entry_from(iter, &encoder->bridge_chain, > chain_node) { > - if (!next->pre_enable_prev_first) { > - next = list_prev_entry(next, chain_node); > + if (!iter->pre_enable_prev_first) { > + next = list_prev_entry(iter, chain_node); > limit = next; > break; > } > -- > 2.43.0 >
