Re: [PATCH v2] drm/mediatek: Remove all conflicting aperture devices during probe
From: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Date: 2026-03-22 13:07:06
Also in:
dri-devel, linux-mediatek, lkml
Hi, Luca: Luca Leonardo Scorcia [off-list ref] 於 2026年2月12日週四 下午7:26寫道：
If a device has a framebuffer available it might be already used as display by simple-framebuffer or simpledrm when mediatek-drm is probed. This is actually helpful when porting to a new device as framebuffers are simple to setup in device trees and fbcon can be used to monitor the kernel boot process. When drm-mediatek loads a new fb device is initialized, however fbcon remains attached to the initial framebuffer which is no longer connected to the actual display - the early fb is never removed. We can gracefully transition from framebuffer handling to drm-managed display by calling aperture_remove_all_conflicting_devices before registering mediatek-drm. This takes care of unloading other fb devices/drivers and disconnects fbcon which then automatically reconnects to mediatekdrmfb as soon as it's available. The function is invoked just before drm_dev_register() to kick out the existing framebuffer as late as possible to reduce the time the screen is unresponsive.
Applied to mediatek-drm-next [1], thanks. [1] https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/log/?h=mediatek-drm-next Regards, Chun-Kuang.
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Signed-off-by: Luca Leonardo Scorcia <redacted> --- v2: Moved the call to aperture_remove_all_conflicting_devices to right before drm_dev_register() drivers/gpu/drm/mediatek/mtk_drm_drv.c | 5 +++++ 1 file changed, 5 insertions(+)diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c index a94c51a83261..02effd9fc698 100644 --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c@@ -4,6 +4,7 @@ * Author: YT SHEN <yt.shen@mediatek.com> */ +#include <linux/aperture.h> #include <linux/component.h> #include <linux/module.h> #include <linux/of.h>@@ -670,6 +671,10 @@ static int mtk_drm_bind(struct device *dev) if (ret < 0) goto err_free; + ret = aperture_remove_all_conflicting_devices(DRIVER_NAME); + if (ret < 0) + dev_err(dev, "Error %d while removing conflicting aperture devices", ret); + ret = drm_dev_register(drm, 0); if (ret < 0) goto err_deinit; --2.43.0