From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A1BB5471CEC for ; Fri, 31 Jul 2026 18:29:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785522575; cv=none; b=WQplABvGU6A5bRgh1wdz08FjANuRresHE51NpXavJIPzbPNME0Xgg2EOe04J+s1f0AtCscSBiO0jJ9VEwsr2aOAYAjutBrT3Ra1A0jreACbwYqy1Mj+IOLbyCcaphROxiFXh2zRpr9rgu4ljFnZjaXh2SwCqO2IS4qabInAtFps= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785522575; c=relaxed/simple; bh=iKaLlrcL5FJcDZMeCe5GsSVaKTbr3DEW/iPGDr4PCw4=; h=From:Subject:To:Cc:In-Reply-To:References:Content-Type:Date: Message-Id; b=DwCRxkrF4yUKC5Wcgqd1pDPCy/2H8T/aK568y3914qN1X/8lxc802w6BAtN6LthUAx4kXIqYD90/yhtq/XzOKzKCH36npN0d1EvazhWDQT1xkm94UfEgfIdzvE0uRgJV6lWp2cAVJGsZW24ka4Xm0bBpR3p+zxUIzQElYwi0/vU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NtgeFNcB; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NtgeFNcB" 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 Reply-To: sashiko-reviews@lists.linux.dev 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> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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