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charset=UTF-8 Date: Tue, 09 Jun 2026 11:30:52 +0200 Message-Id: Subject: Re: [PATCH 26/37] drm: event-notifier: add mechanism to notify about hotplug events Cc: "Maarten Lankhorst" , "Thomas Zimmermann" , "David Airlie" , "Simona Vetter" , "Andrzej Hajda" , "Neil Armstrong" , "Robert Foss" , "Laurent Pinchart" , "Jonas Karlman" , "Jernej Skrabec" , "Inki Dae" , "Jagan Teki" , "Marek Szyprowski" , "Marek Vasut" , "Stefan Agner" , "Frank Li" , "Sascha Hauer" , "Pengutronix Kernel Team" , "Fabio Estevam" , "Hui Pu" , "Ian Ray" , "Thomas Petazzoni" , , , , To: "Maxime Ripard" , "Luca Ceresoli" From: "Luca Ceresoli" X-Mailer: aerc 0.21.0 References: <20260519-drm-bridge-hotplug-v1-0-45e2bdb3dfb4@bootlin.com> <20260519-drm-bridge-hotplug-v1-26-45e2bdb3dfb4@bootlin.com> <20260608-maize-rooster-of-youth-c0bbde@houat> In-Reply-To: <20260608-maize-rooster-of-youth-c0bbde@houat> X-Last-TLS-Session-Version: TLSv1.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260609_103108_288442_CF2FA06F X-CRM114-Status: GOOD ( 13.54 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon Jun 8, 2026 at 2:13 PM CEST, Maxime Ripard wrote: > On Tue, May 19, 2026 at 12:37:43PM +0200, Luca Ceresoli wrote: >> In preparation for supporting DRM bridge hotplug, add an event notifier = to >> allow interested parties to be notified about events they need to react = to. >> >> For the initial implementation of bridge hotplug, two events are needed: >> bridge detach (happening in drm_bridge.c) and MIPI device attach to MIPI >> host (happening in drm_mipi_dsi.c). >> >> For this reason implement the event notifier in a new common file that >> event producers can easily use to send events. >> >> Signed-off-by: Luca Ceresoli > > So, you claim in the commit message that it's about a hotplug event, but > the only events are the bridge being attached and detached, so not a > hotplug event? > > And why a bridge would want to be notified that itself (or another?) > bridge is being attached or detached? > > You need documentation, and a more descriptive commit message. Yes. But before that I need a decision about the scope we want to give to this notifier. It is a very generic module, with basically no dependencies, so people will try to add more unrelated events and we'd need to set a boundary. Options: * Should it be for hotplug-related events only? * Should it be for any DRM event that needs notifications? * Something else? I'm happy to write that in the docs and commit message once it's agreed, so any comments would be welcome right now. Luca -- Luca Ceresoli, Bootlin Embedded Linux and Kernel engineering https://bootlin.com