From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout-p-202.mailbox.org (mout-p-202.mailbox.org [80.241.56.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DFECA3446CB for ; Fri, 17 Apr 2026 16:08:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=80.241.56.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776442104; cv=none; b=WeFQu3jsVO/o1LWT2eL+27zkYeVSy8pEeNjqbiRmO9KM3Zw4cd6v47VIenpJV4c1kxD0qJes9DyA9qTP6I2rXjErUG0b2wAXBeSHzny6voB7ZWAcyEoDWPwJS0TB47biJAx1yw6lUWK7z8HTi4q0Krur7HQLsGLqVXBqWDTnqDs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776442104; c=relaxed/simple; bh=CtAebwgQOxE5Wi5XVrETbPpoAcpXcQM4i2W4b6Y3MJg=; h=Message-ID:Date:MIME-Version:Subject:From:To:Cc:References: In-Reply-To:Content-Type; b=cGyRnyS4DUyH/XvP3Q9oNv0dHmDIaX95HLYJg5DBInGKxirsipN9U0NMClO1GL91IQSrWFrflvEz+NfATY3inlTt4BUgrjioYn9bNZvZHdyyjhhgSz7awqjn1qggT/Efi5V0eWE527se9N0grE5sh8/R3IFDFC+ysRw6eshWo9A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org; spf=pass smtp.mailfrom=mailbox.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b=wGZcKlC+; arc=none smtp.client-ip=80.241.56.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=mailbox.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mailbox.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=mailbox.org header.i=@mailbox.org header.b="wGZcKlC+" Received: from smtp2.mailbox.org (smtp2.mailbox.org [IPv6:2001:67c:2050:b231:465::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mout-p-202.mailbox.org (Postfix) with ESMTPS id 4fy0Cw1dHpz9v1C; Fri, 17 Apr 2026 18:08:12 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mailbox.org; s=mail20150812; t=1776442092; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=EEOhFI6FMsYr3RqKHmLgf8SxXkclhRS7RnspH6Yfq0g=; b=wGZcKlC+Heacy4BW43Xr5h4S0JK+GbQFfYPP3fnrP0ScSl5R91M/E+N/PWsw4j2pz1/X6c sEVZeQYT6XwXuLafjnxY0TlAJAQYSeVpt8lOyZoTS7hDL2PjDDnKiKWN4lnyf9vzB4IQ+8 k7wExmm+GYZvNHjTUwJCBtOOPG4KhZeiWz1uTX/cvWS3ZhQOcC4Lh2BM+dRT4YpZaVLW8F aOLw1GHNqv91vKq3ZLai/lF81MnNgzLklhe16aFF2CEr6HqF0Dj+I9nVmT3uCqbgwGHINI s+q2g6lbbZ/zVHcPfzYu+X2EdxvrNqFlL2GMxYNjGs314r90X/W3F/+48E8Hkw== Message-ID: <07072379-32c8-4912-8539-7fa590abf544@mailbox.org> Date: Fri, 17 Apr 2026 18:08:05 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v3 1/2] drm: introduce KMS recovery mechanism From: =?UTF-8?Q?Michel_D=C3=A4nzer?= To: Hamza Mahfooz Cc: Mario Limonciello , dri-devel@lists.freedesktop.org, Harry Wentland , Leo Li , Rodrigo Siqueira , Alex Deucher , =?UTF-8?Q?Christian_K=C3=B6nig?= , David Airlie , Simona Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , Alex Hung , Wayne Lin , Aurabindo Pillai , Ivan Lipski , =?UTF-8?Q?Timur_Krist=C3=B3f?= , Dominik Kaszewski , amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= References: <20260212230905.688006-1-someguy@effective-light.com> <2e359cd9-0192-44d0-886f-7f93a8b0a4fa@amd.com> <85319290-4027-4eb8-95d1-9009d23f2294@mailbox.org> <7f4a86ad-d642-444c-a576-17ff9caaa934@mailbox.org> <8588dcbc-621e-43db-9d69-32398f75d9e6@mailbox.org> Content-Language: de-CH-frami, en-CA In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-MBO-RS-ID: 7bd649e8221e05cb222 X-MBO-RS-META: 9tfp87rtgrzx9dptw3urqkdx3rj9fxm5 On 2/20/26 10:09, Michel Dänzer wrote: > On 2/20/26 09:42, Michel Dänzer wrote: >> On 2/18/26 10:22, Michel Dänzer wrote: >>> On 2/18/26 01:45, Hamza Mahfooz wrote: >>>> On Mon, Feb 16, 2026 at 10:28:13AM +0100, Michel Dänzer wrote: >>>>> On 2/14/26 23:16, Hamza Mahfooz wrote: >>>>>> On Sat, Feb 14, 2026 at 03:02:49PM +0100, Michel Dänzer wrote: >>>>>> >>>>>>> In principle it's possible to do (the equivalent of) a modeset with the current state for all CRTCs, no need to do it separately per CRTC. >>>>>> >>>>>> AFAIK that is what the uevent is already doing (unless I'm mistaken). >>>>> >>>>> This is about just doing a full modeset, which isn't something user space can do in response to a wedged event. >>>> >>>> I was referring to what compositors are doing in response to >>>> `drm_kms_helper_hotplug_event()`. Perhaps, the enum constants should be >>>> renamed, since the forced modeset is actually sent when the current >>>> reset phase is DRM_KMS_RESET_NONE (the phase is updated before sending >>>> out the event though). >>> >>> Ah, you're talking about the drm_kms_helper_hotplug_event call in drm_atomic_helper_wait_for_flip_done (I thought "uevent" referred to drm_dev_wedged_event in patch 2). >>> >>> I don't know about other compositors, but I don't think mutter will do a modeset in response to a hotplug event if no KMS state changed (because some monitors can generate spurious hotplug events). >> >> [...] > > [...], a reason why the kernel can't just do a modeset itself occurred to me: A modeset might affect other CRTCs than the ones affected by the timed-out commit, which could interact badly with other pending commits affecting those other CRTCs. In a different thread, Ville (added to Cc) said this shouldn't be an issue. In which case this would seem like the simplest solution. -- Earthling Michel Dänzer \ GNOME / Xwayland / Mesa developer https://redhat.com \ Libre software enthusiast