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Tue, 18 Aug 2026 19:39:15 +0000 Date: Tue, 18 Aug 2026 21:39:13 +0200 From: Francesco Valla To: =?utf-8?B?TcOgeGlt?= Pedraza Padilla Cc: Sam Ravnborg , Maxime Ripard , Helge Deller , Uwe =?utf-8?Q?Kleine-K=C3=B6nig?= , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Thomas Zimmermann , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: Re: [RFC PATCH 0/6] Boot logo supplied by the device tree Message-ID: References: <20260731215043.30392-1-maximpedraza@gmail.com> <0219df57-06e3-4776-afb1-d167cad2e795@gmx.de> <20260810-devout-pig-of-performance-595ccc@houat> <20260812-neon-asp-of-completion-e9349e@houat> <20260814155325.GB516994@ravnborg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - esm19.siteground.biz X-AntiAbuse: Original Domain - lists.freedesktop.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - valla.it X-Source: X-Source-Args: X-Source-Dir: X-SGantispam-id: 7590a7fdef1e3d3ac838eb8da61eb77f X-AntiAbuse: ID - 7590a7fdef1e3d3ac838eb8da61eb77f AntiSpam-DLS: false AntiSpam-DLSP: AntiSpam-DLSRS: AntiSpam-TS: 1.0 CFBL-Address: feedback@antispam.mailspamprotection.com; report=arf CFBL-Feedback-ID: 1wwPep-00000004UZm-3GUS-feedback@antispam.mailspamprotection.com Authentication-Results: outgoing.instance-europe-west4-tvch.prod.antispam.mailspamprotection.com; iprev=pass (214.173.214.35.bc.googleusercontent.com) smtp.remote-ip=35.214.173.214; auth=pass (LOGIN) smtp.auth=esm19.siteground.biz; dkim=pass header.d=valla.it header.s=default header.a=rsa-sha256; arc=none X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Màxim, On Tue, Aug 18, 2026 at 12:48:21AM +0200, Màxim Pedraza Padilla wrote: > Hi Sam, > > Thank you -- that's a useful pointer, and it settles the question of how > a splash should be drawn without fbcon: a DRM client at > drm_client_setup(), next to drm_log, not a drm_fb_helper hook. > > Francesco's series is genuinely inspiring work, and it would be very > useful to me if it could take a CLUT224 image -- unfortunately it can't. > It only accepts an uncompressed 24-bit RGB888 BMP, whereas our logo is > paletted, which is what keeps it small: 17 KiB for 800x480 rather than > around a megabyte. So as it stands the format doesn't line up with what > we carry. Format concerns are - in addition to lack of time to work on it - what is keeping me from sending a new revision. Any kind of compression would need to be unwinded - probably on a per-pixel basis - making the required CPU time unreasonable for large images (at least if boot time optimization is the ultimate goal - linke in my case). Of course, on "low-resolution" displays the size-vs-time tradeoff might be the sweet spot - but the target here was to being as much generic as possible. > > Reading it did make the distinction clearer to me, though. drm_splash > *draws* an image into a fresh buffer, which means a first modeset and the > blanking that comes with it. What our hardware leaves us with is a > framebuffer U-Boot has already drawn and a CRTC still scanning it out, so > for our case the natural thing is to *adopt* that state rather than > redraw it -- which is what hardware state readout does, with no redraw > and no flicker. > > Where drm_splash is the right tool is the case with no state to adopt -- > Falcon boot, where U-Boot proper never runs, or a handover where the > buffer doesn't survive. I'll follow Francesco's series for that. My typical embedded setup is exactly that one - Falcon boot, a simple boot logic inside the SPL, and possibly no initramfs. I find this to be the most portable solution, as it does not require complex drivers and handover logic in the bootloader. In case you decide to take my series for a re-spin, feel free to ask if something is unclear. > Thanks again -- it helped me draw the line between the two. > > Max Reagrds, Francesco