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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D4B52CD5BC8 for ; Tue, 26 May 2026 12:35:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=oQ+OHMp99D8xoRZvJBBEvxSuLKoEVBXtdAFFTNEa6Rw=; b=IEJ9VAVtjzxV50UROgtrP2tXIR zm/Q3i+tE/fNa9DV003I31ChMDtWvQxR/TTgPkgrv/NCFaAi7tbtuj66r3a+KTygUFAQKXumX9QxY RMN1AeAOR95bn3qOSV0pEvr+nDOGoL6DxnduO2hj0K+fIFu0Y7itxzjNfb3NkDvH4kwcfdQEXDM5g 9nC/uXBJ5iOhttxZDqhLTFZKHoN5aI3S72eCYSXnYOqFXmaqZs22lv0trWQjYDDDQN2cf1lt8xUWy MNQn3/i4mpF0SHuSguKfl6trxiz9GXpJMP3kkCYYOzr29EmGp3VzgAY+kdBg6Q2GN+jm21ckyXwHP wnAN1o8g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wRr0b-00000001veH-3Of4; Tue, 26 May 2026 12:35:45 +0000 Received: from mail-m816.xmail.ntesmail.com ([156.224.81.6]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wRr0Y-00000001vdC-2mus; Tue, 26 May 2026 12:35:44 +0000 Received: from [172.16.12.74] (unknown [61.154.14.86]) by smtp.qiye.163.com (Hmail) with ESMTP id 3fe38e512; Tue, 26 May 2026 20:35:31 +0800 (GMT+08:00) Message-ID: <00565241-3962-4418-8711-859dc98dba13@rock-chips.com> Date: Tue, 26 May 2026 20:35:30 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 2/2] drm/bridge: analogix_dp: Add support for optional data-lanes mapping To: Luca Ceresoli , Marek Szyprowski Cc: hjc@rock-chips.com, heiko@sntech.de, andy.yan@rock-chips.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, Laurent.pinchart@ideasonboard.com, jonas@kwiboo.se, jernej.skrabec@gmail.com, nicolas.frattaroli@collabora.com, cristian.ciocaltea@collabora.com, sebastian.reichel@collabora.com, dmitry.baryshkov@oss.qualcomm.com, dianders@chromium.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org References: <20260525094731.121380-1-damon.ding@rock-chips.com> <20260525094731.121380-3-damon.ding@rock-chips.com> <177979727057.297330.10691183273720133245.b4-review@b4> Content-Language: en-US From: Damon Ding In-Reply-To: <177979727057.297330.10691183273720133245.b4-review@b4> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-HM-Tid: 0a9e6448786d03a8kunm591ab7c8b8886b X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWRgWCB1ZQUpXWS1ZQUlXWQ8JGhUIEh9ZQVkZHktNVhhKTRhCH0gaHxoaTlYVFA kWGhdVEwETFhoSFyQUDg9ZV1kYEgtZQVlNSlVKTk9VSk9VQ01ZV1kWGg8SFR0UWUFZT0tIVUpLSE pKQk1VSktLVUpCWQY+ DKIM-Signature: a=rsa-sha256; b=Mri3/IGcBzNc+G9t8s5zfRoweaS3NFeHeZAVbKn66fIdfriaFiCCbSNgVT9cecYd24uwwupB6hn52vIM91IrI4Vc2uMrMpQwV1SrQ8zA1M2u2YsdZRT9h1lZC4z+ANp/d5pgObI9xFP5vO798m9/dNx7HD/Gkg8btotIad81iTk=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=oQ+OHMp99D8xoRZvJBBEvxSuLKoEVBXtdAFFTNEa6Rw=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260526_053543_291719_06E8579E X-CRM114-Status: GOOD ( 14.36 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Luca, On 5/26/2026 8:07 PM, Luca Ceresoli wrote: > On Mon, 25 May 2026 17:47:31 +0800, Damon Ding wrote: > > Hello Damon, > >> >> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> index 8cf6b73bceac..d53ab25bc57b 100644 >> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c >> @@ -1234,6 +1234,59 @@ static const struct drm_bridge_funcs analogix_dp_bridge_funcs = { >> [ ... skip 11 lines ... ] >> + int ret, i; >> + >> + memcpy(video_info->lane_map, map, sizeof(map)); >> + >> + num_lanes = drm_of_get_data_lanes_count_ep(dp->dev->of_node, 1, 0, 1, >> + video_info->max_lane_count); > > Should num_lanes be > 4, the buffers could overflow. I realize it should > not happen, but analogix_dp_dt_parse_pdata() can set max_lane_count from > the device tree, so a bogus dtb could cause such overflow. > > Perhaps you should just (in a separate patch) error out in > analogix_dp_dt_parse_pdata() to prevent this. And maybe even adding an > BUG_ON(lane_count > 4) here. > > Otherwise LGTM. > Thank you for the review. I think it would be a better idea to add a separate patch to validate the max_link_rate and max_lane_count values for Exynos DP. I checked the Exynos DP related DTS files: - The maximum value of samsung,lane-count is 4 - The maximum value of samsung,link-rate is 0x0a, which corresponds to the HBR lane rate. Could Marek please help confirm if we can set these as the upper limits for the checks? Best regards, Damon