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(unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 4bab2d5a4; Fri, 28 Aug 2026 14:52:05 +0800 (GMT+08:00) From: Damon Ding To: Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Sandy Huang , Heiko Stuebner , Andy Yan Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Dmitry Baryshkov , Marek Szyprowski , Sebastian Reichel , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Damon Ding Subject: [PATCH v8 2/5] drm/dp: Add helper to validate DP lane counts Date: Fri, 28 Aug 2026 14:51:50 +0800 Message-Id: <20260828065153.590802-3-damon.ding@rock-chips.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260828065153.590802-1-damon.ding@rock-chips.com> References: <20260828065153.590802-1-damon.ding@rock-chips.com> MIME-Version: 1.0 X-HM-Tid: 0aa04723d5e203a8kunm9cc188d518834a X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1kYFggdWUFKV1ktWUFJV1kPCRoVCBIfWUFZGk4aGlYaSEMdSEsZSU IeQ0lWFRQJFhoXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0 tIVUpLSU9PT0hVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=J3ln/bxybGTsOfkGBbZzKL9bXT2jZ9+ygl5ZAisrNMxtrVWSl2FG5ZFDMbj6iGPWwecOCgPNJFC+PF3O1qIsbsDr/VcpySVQUJRnOxamoNBrZvltJ9/Duo8jBMIzVAjRuvyhGVnF5/X9fvXA1sjPqaTYubqoh+eUn2HVj5d3WX0=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=3D3tCxbxiOqvsJFvLlKoOy9RkGLmHyoV0izPMCA9ZDc=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260827_235214_518893_7988638F X-CRM114-Status: UNSURE ( 7.03 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-rockchip@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Upstream kernel work for Rockchip platforms List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-rockchip" Errors-To: linux-rockchip-bounces+linux-rockchip=archiver.kernel.org@lists.infradead.org Add a generic helper function drm_dp_lane_count_is_valid() to check if a DisplayPort lane count is valid. According to the DP specification, only 1, 2, or 4 lanes are supported. This helper avoids duplicating DP lane count validation logic across individual DisplayPort drivers. Suggested-by: Luca Ceresoli Reviewed-by: Luca Ceresoli Signed-off-by: Damon Ding --- Changes in v6: - Add Reviewed-by tag. --- include/drm/display/drm_dp_helper.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index ab16c1be3900..5b05a7fbe174 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -139,6 +139,12 @@ bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_C int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]); +static inline bool +drm_dp_lane_count_is_valid(int lane_count) +{ + return lane_count == 1 || lane_count == 2 || lane_count == 4; +} + static inline int drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { -- 2.34.1 _______________________________________________ Linux-rockchip mailing list Linux-rockchip@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-rockchip 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 D27C9C61DB9 for ; Fri, 28 Aug 2026 06:52:28 +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: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=3D3tCxbxiOqvsJFvLlKoOy9RkGLmHyoV0izPMCA9ZDc=; b=gF1GrAN5tKbCVZbNvA8wEtZa8S vaTFE/a1c4ekj7+bhQEuWIPRgWTaoFhlpPkRd/smF3V0naMzBpDECrTWgUcQ+7C1kmPrqjwFUlZ7I KBp7Sauck2EmRbEyzNjdqh3EinxnO2VHvKbx20B6D/N2rdt2uTIBopPh6xcyVSvoR6wS6E3jMmdYV g4vzC7ibkkzYE012QNxiIkP1CW9RWrrdG2bYkJ8iXZigeXQHpVt7bv6XPQzzK+USEOSmihxOP/Tm6 KA89gXQLkQjtDOSJ1imvqx0sIiR8flpNmEW5NGZ2/iLqS01h2fE5xwicy78wTPoE+DV3FkrjXh0EN cq9AIXWQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzqRl-00000005Dnj-45lv; Fri, 28 Aug 2026 06:52:17 +0000 Received: from mail-m83105.xmail.ntesmail.com ([156.224.83.105]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wzqRh-00000005Dko-3a2d; Fri, 28 Aug 2026 06:52:16 +0000 Received: from zyb-HP-ProDesk-680-G2-MT.. (unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 4bab2d5a4; Fri, 28 Aug 2026 14:52:05 +0800 (GMT+08:00) From: Damon Ding To: Andrzej Hajda , Neil Armstrong , Robert Foss , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Sandy Huang , Heiko Stuebner , Andy Yan Cc: Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Luca Ceresoli , Dmitry Baryshkov , Marek Szyprowski , Sebastian Reichel , dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org, Damon Ding Subject: [PATCH v8 2/5] drm/dp: Add helper to validate DP lane counts Date: Fri, 28 Aug 2026 14:51:50 +0800 Message-Id: <20260828065153.590802-3-damon.ding@rock-chips.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260828065153.590802-1-damon.ding@rock-chips.com> References: <20260828065153.590802-1-damon.ding@rock-chips.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-HM-Tid: 0aa04723d5e203a8kunm9cc188d518834a X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1kYFggdWUFKV1ktWUFJV1kPCRoVCBIfWUFZGk4aGlYaSEMdSEsZSU IeQ0lWFRQJFhoXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0 tIVUpLSU9PT0hVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=J3ln/bxybGTsOfkGBbZzKL9bXT2jZ9+ygl5ZAisrNMxtrVWSl2FG5ZFDMbj6iGPWwecOCgPNJFC+PF3O1qIsbsDr/VcpySVQUJRnOxamoNBrZvltJ9/Duo8jBMIzVAjRuvyhGVnF5/X9fvXA1sjPqaTYubqoh+eUn2HVj5d3WX0=; c=relaxed/relaxed; s=default; d=rock-chips.com; v=1; bh=3D3tCxbxiOqvsJFvLlKoOy9RkGLmHyoV0izPMCA9ZDc=; h=date:mime-version:subject:message-id:from; X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260827_235214_518893_7988638F X-CRM114-Status: UNSURE ( 7.03 ) X-CRM114-Notice: Please train this message. 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 Add a generic helper function drm_dp_lane_count_is_valid() to check if a DisplayPort lane count is valid. According to the DP specification, only 1, 2, or 4 lanes are supported. This helper avoids duplicating DP lane count validation logic across individual DisplayPort drivers. Suggested-by: Luca Ceresoli Reviewed-by: Luca Ceresoli Signed-off-by: Damon Ding --- Changes in v6: - Add Reviewed-by tag. --- include/drm/display/drm_dp_helper.h | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/include/drm/display/drm_dp_helper.h b/include/drm/display/drm_dp_helper.h index ab16c1be3900..5b05a7fbe174 100644 --- a/include/drm/display/drm_dp_helper.h +++ b/include/drm/display/drm_dp_helper.h @@ -139,6 +139,12 @@ bool drm_dp_as_sdp_supported(struct drm_dp_aux *aux, const u8 dpcd[DP_RECEIVER_C int drm_dp_psr_setup_time(const u8 psr_cap[EDP_PSR_RECEIVER_CAP_SIZE]); +static inline bool +drm_dp_lane_count_is_valid(int lane_count) +{ + return lane_count == 1 || lane_count == 2 || lane_count == 4; +} + static inline int drm_dp_max_link_rate(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { -- 2.34.1