From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6EB97C5DF8C for ; Sun, 23 Aug 2026 12:00:43 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 22E6410E4FD; Sun, 23 Aug 2026 12:00:41 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="mRoKOmML"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5658910E4B2 for ; Sun, 23 Aug 2026 12:00:40 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id E59A340298; Sun, 23 Aug 2026 12:00:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7B3B1F000E9; Sun, 23 Aug 2026 12:00:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787486439; bh=vA1RqKqhZ+NvoAm5sf8HqGP8jYQhtr6Ury50/r4g9rU=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=mRoKOmMLeNToRfPKPpBoCuENQ59/6JuhFjou26zuz1HKxY+iTyLXfm9hVKYvQOUYS Y83sbrRFnPNP7gEq0CMQzlG9/5G/JZ1GnrgVkm0UzTeWyPJPJvLWxnnc0/sT89RvLC 5K6/l9ii8ST/seuAlEEme1g1GiHS/Lyp+Np6jrHylsrXxzaXGGctOzf29RhTHNTfU+ BY5l27fUXOedieX9YYzySgF0ia5+HUPEz0LFsn5vsfuPhgd3Tv76/J+LJoCv8ZgPO0 KanRhLWn90P7yFCNNUpBqMw3tXUSYPFKjXRKuVHCKHiuCmc2XbwZfrS/179FDCQPJv bxD1u3tjKhLxQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v2] drm/amd/display: Restore self-refresh fallback in DCN21 bandwidth validation To: "Julien Le Bourg" Cc: dri-devel@lists.freedesktop.org In-Reply-To: <20260823115200.12502-1-julien.lebourg8@gmail.com> References: <20260822091715.6692-1-julien.lebourg8@gmail.com> <20260823115200.12502-1-julien.lebourg8@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Sun, 23 Aug 2026 12:00:39 +0000 Message-Id: <20260823120039.A7B3B1F000E9@smtp.kernel.org> 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: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] The stutter latency leak fixed for DCN 2.1 is explicitly left unpa= tched for DCN 3.01, leaving it vulnerable to MPO flip_done timeouts. -- --- Patch [1]: [PATCH v2] drm/amd/display: Restore self-refresh fallback in= DCN21 bandwidth validation --- commit 65e2baa225f2dd040a51a1cbfe0d3ae3aa5e8b28 Author: Julien Le Bourg drm/amd/display: Restore self-refresh fallback in DCN21 bandwidth validation This commit restores the self-refresh fallback in DCN21 bandwidth validation to allow short-vblank eDP timings to validate. It also addresses a state le= ak in the DCN21 watermark calculation by saving and restoring the stutter latencies. Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/5628 > dcn301_fpu.c has the same helper and the same restore gap. Left alone; > I cannot test DCN 3.01. [Severity: High] This isn't a bug introduced by this patch, but since the stutter latency leak is explicitly left unpatched for DCN 3.01, will it remain vulnerable to MPO flip_done timeouts? In drivers/gpu/drm/amd/display/dc/dml/dcn301/dcn301_fpu.c, when dcn301_fpu_calculate_wm_and_dlg() calculates watermarks, it calls calculate_wm_set_for_vlevel() which mutates the latencies without restoring them: calculate_wm_set_for_vlevel() ... dml->soc.sr_exit_time_us =3D table_entry->sr_exit_time_us; dml->soc.sr_enter_plus_exit_time_us =3D table_entry->sr_enter_plus_exit_ti= me_us; Does this state mismatch between atomic_check and commit_tail cause flip_do= ne timeouts under MPO on DCN 3.01 hardware where p-state switching is possible, potentially leading to display freezes or compositor crashes? Should the same snapshot and restore fix be applied to dcn301_fpu.c to prevent this leak into dc->current_state? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260823115200.1250= 2-1-julien.lebourg8@gmail.com?part=3D1