From nobody Tue Apr 7 03:32:50 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DC53C38A2D for ; Wed, 26 Oct 2022 18:29:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234133AbiJZS32 (ORCPT ); Wed, 26 Oct 2022 14:29:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56710 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234345AbiJZS2u (ORCPT ); Wed, 26 Oct 2022 14:28:50 -0400 Received: from relay08.th.seeweb.it (relay08.th.seeweb.it [5.144.164.169]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C28A8DD896 for ; Wed, 26 Oct 2022 11:28:49 -0700 (PDT) Received: from localhost.localdomain (94-209-172-39.cable.dynamic.v4.ziggo.nl [94.209.172.39]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by m-r2.th.seeweb.it (Postfix) with ESMTPSA id 3CAE13F33A; Wed, 26 Oct 2022 20:28:47 +0200 (CEST) From: Marijn Suijten To: phone-devel@vger.kernel.org, Rob Clark , Abhinav Kumar , Dmitry Baryshkov , Vinod Koul Cc: ~postmarketos/upstreaming@lists.sr.ht, AngeloGioacchino Del Regno , Konrad Dybcio , Martin Botka , Jami Kettunen , Marijn Suijten , Sean Paul , David Airlie , Daniel Vetter , Douglas Anderson , Vladimir Lypak , linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH v4 08/10] drm/msm/dsi: Disallow 8 BPC DSC configuration for alternative BPC values Date: Wed, 26 Oct 2022 20:28:22 +0200 Message-Id: <20221026182824.876933-9-marijn.suijten@somainline.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221026182824.876933-1-marijn.suijten@somainline.org> References: <20221026182824.876933-1-marijn.suijten@somainline.org> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" According to the `/* bpc 8 */` comment below only values for a bits_per_component of 8 are currently hardcoded in place. This is further confirmed by downstream sources [1] containing different constants for other BPC values (and different initial_offset too, with an extra dependency on bits_per_pixel). Prevent future mishaps by explicitly disallowing any other bits_per_component value until the right parameters are put in place and tested. [1]: https://git.codelinaro.org/clo/la/platform/vendor/opensource/display-d= rivers/-/blob/DISPLAY.LA.2.0.r1-08000-WAIPIO.0/msm/sde_dsc_helper.c#L110-139 Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Reviewed-by: Dmitry Baryshkov Signed-off-by: Marijn Suijten --- drivers/gpu/drm/msm/dsi/dsi_host.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/d= si_host.c index 8da27c740c1c..4bd8301d2049 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1783,6 +1783,11 @@ static int dsi_populate_dsc_params(struct msm_dsi_ho= st *msm_host, struct drm_dsc return -EINVAL; } =20 + if (dsc->bits_per_component !=3D 8) { + DRM_DEV_ERROR(&msm_host->pdev->dev, "DSI does not support bits_per_compo= nent !=3D 8 yet\n"); + return -EOPNOTSUPP; + } + dsc->rc_model_size =3D 8192; dsc->first_line_bpg_offset =3D 12; dsc->rc_edge_factor =3D 6; --=20 2.38.1