Hi, Thanks for your answer On Mon, Feb 17, 2025 at 05:41:24PM +0100, Simona Vetter wrote: > On Thu, Feb 13, 2025 at 03:43:50PM +0100, Maxime Ripard wrote: > > Now that connectors are no longer necessarily created by the bridges > > drivers themselves but might be created by drm_bridge_connector, it's > > pretty hard for bridge drivers to retrieve pointers to the connector and > > CRTC they are attached to. > > > > Indeed, the only way to retrieve the CRTC is to follow the drm_bridge > > encoder field, and then the drm_encoder crtc field, both of them being > > deprecated. > > Eh, this isn't quite how this works. So unless bridges have become very > dynamic and gained flexible routing the bridge(->bridge->...)->encoder > chain is static. And the crtc for an encoder you find by walking the > connector states in a drm_atomic_state, finding the right one that points > at your encoder, and then return the ->crtc pointer from that connector > state. > > It's a bit bonkers, but I think it's better to compute this than adding > more pointers that potentially diverge. Unless there's a grand plan here, > but then I think we want some safety checks that all the pointers never > get out of sync here. That work stemed from this series https://lore.kernel.org/all/20250210132620.42263-1-herve.codina@xxxxxxxxxxx/ and in particular: https://lore.kernel.org/all/20250210132620.42263-5-herve.codina@xxxxxxxxxxx/ Bridges, outside of the modesetting code path, don't have a way to access the drm_atomic_state since drm_bridge_state->state is typically cleared after swap_state. So accessing the connectors and CRTCs don't work anymore. In this particular case, we needed to access those from the bridge interrupt handler. Maxime
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