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 D3F35C55174 for ; Fri, 31 Jul 2026 18:29:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 43A8110E0F7; Fri, 31 Jul 2026 18:29:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="NtgeFNcB"; dkim-atps=neutral Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by gabe.freedesktop.org (Postfix) with ESMTPS id A7B4B10E0F7 for ; Fri, 31 Jul 2026 18:29:35 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 877D8600C3; Fri, 31 Jul 2026 18:29:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EAF081F00AC4; Fri, 31 Jul 2026 18:29:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785522574; bh=HBY+A5rlhzdFyquEWiYW2ZRVN2OC91gRWqsnex5DLOE=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=NtgeFNcBUGKfkQGB93yJSf0l24rk6sCsJ+cJGsC9Sc3pygSFgLXCvMK3ovyTdo6VQ tDsNyatzQAM6Pw+yNSfdbcX0JNS+H8YwFGJjfgLOevUYQgqQNgg8QdsHRTpjf/eevL DRgZR+cUfHTKwDX07qTRAM/6OyW+30sf9gDp02HFvqwavrw9j1QuDk4CbfDT4bHAQh FBd/zRUFsc96lxQ7GV1o0tcKbjPJAwOgVCcVTSkG3OT/wRilPgCdZ76hyrJDi07HBP ryjFb+liD8367XW5UYcO8gBQBLfUMFaWoQd7UK1XTS43aF3D8OKSnItgbshr0SGyka 7MTvqiYyGGu9A== From: sashiko-bot@kernel.org Subject: Re: [PATCH v8 19/21] drm/bridge: synopsys: dw-dp: Use regmap_set_bits in dw_dp_send_sdp To: "Sebastian Reichel" Cc: conor+dt@kernel.org, devicetree@vger.kernel.org, robh@kernel.org, dri-devel@lists.freedesktop.org In-Reply-To: <20260731-synopsys-dw-dp-improvements-v8-19-ac1e6a75782f@collabora.com> References: <20260731-synopsys-dw-dp-improvements-v8-0-ac1e6a75782f@collabora.com> <20260731-synopsys-dw-dp-improvements-v8-19-ac1e6a75782f@collabora.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 31 Jul 2026 18:29:32 +0000 Message-Id: <20260731182933.EAF081F00AC4@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: - [High] A mutex is acquired in dw_dp_send_sdp(), which is called from the = bridge's atomic enable path, violating atomic context rules. -- --- Patch [19]: [PATCH v8 19/21] drm/bridge: synopsys: dw-dp: Use regmap_se= t_bits in dw_dp_send_sdp --- commit fbf6588f46fe1b8bc7ef347644cccb5c7a752410 Author: Sebastian Reichel drm/bridge: synopsys: dw-dp: Use regmap_set_bits in dw_dp_send_sdp This commit simplifies dw_dp_send_sdp() by making use of regmap_set_bits instead of regmap_update_bits. No functional change is intended. > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-dp.c b/drivers/gpu/drm/br= idge/synopsys/dw-dp.c > --- a/drivers/gpu/drm/bridge/synopsys/dw-dp.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-dp.c > @@ -1070,14 +1070,12 @@ static int dw_dp_send_sdp(struct dw_dp *dp, struc= t dw_dp_sdp *sdp) [Severity: High] Does this function sleep in an atomic context? Looking at dw_dp_send_sdp(), it acquires a sleeping lock via scoped_guard(mutex, &dp->sdp_lock) earlier in the function. However, this is called from the bridge's atomic enable path: drm_atomic_helper_commit_tail() -> dw_dp_bridge_atomic_enable() -> dw_dp_video_enable() -> dw_dp_send_vsc_sdp() -> dw_dp_send_sdp() Can this sequence cause a kernel splat ("BUG: sleeping function called from invalid context") or potential deadlocks when modesetting, since it executes within drm_atomic_helper_commit_tail() where sleeping is forbidden? > FIELD_PREP(SDP_REGS, get_unaligned_le32(payload))); > =20 > if (sdp->flags & DW_DP_SDP_VERTICAL_INTERVAL) > - regmap_update_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL, > - EN_VERTICAL_SDP << nr, > - EN_VERTICAL_SDP << nr); > + regmap_set_bits(dp->regmap, DW_DP_SDP_VERTICAL_CTRL, > + EN_VERTICAL_SDP << nr); > =20 > if (sdp->flags & DW_DP_SDP_HORIZONTAL_INTERVAL) > - regmap_update_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL, > - EN_HORIZONTAL_SDP << nr, > - EN_HORIZONTAL_SDP << nr); > + regmap_set_bits(dp->regmap, DW_DP_SDP_HORIZONTAL_CTRL, > + EN_HORIZONTAL_SDP << nr); > =20 > return nr; > } --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260731-synopsys-d= w-dp-improvements-v8-0-ac1e6a75782f@collabora.com?part=3D19