From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 07B061863 for ; Wed, 28 Dec 2022 15:35:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8330DC433EF; Wed, 28 Dec 2022 15:35:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672241753; bh=papQIDW4JSpVVO8bJDvnuPBr9IByYZ+9llNrpSBn7Pg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cg8GgQn9EPr8ex9/HNNxC18YVWsHcxCEM6OvJ46+DyYyF/Xbdejx68Uyupljqc4BY xnnwD6k7vIWii5p9B4EIBQxHPyiJTMtRhT3H2inenaH9rlarTVoabx18N1/2Uc9VnX LdpW1AJuomRyFxG5xeiPXOQ1dIpz3Zm7uVa8L15o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dmitry Baryshkov , Marijn Suijten , Sasha Levin Subject: [PATCH 6.1 0285/1146] drm/msm/dsi: Disallow 8 BPC DSC configuration for alternative BPC values Date: Wed, 28 Dec 2022 15:30:24 +0100 Message-Id: <20221228144337.881757585@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144330.180012208@linuxfoundation.org> References: <20221228144330.180012208@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Marijn Suijten [ Upstream commit d053fbc449c47517b1f6516dbce2f917f2a9f51d ] 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-drivers/-/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 Patchwork: https://patchwork.freedesktop.org/patch/508942/ Link: https://lore.kernel.org/r/20221026182824.876933-9-marijn.suijten@somainline.org Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin --- 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/dsi_host.c index de00925c94e8..c229cf6eeb9c 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1761,6 +1761,11 @@ static int dsi_populate_dsc_params(struct msm_dsi_host *msm_host, struct drm_dsc return -EINVAL; } + if (dsc->bits_per_component != 8) { + DRM_DEV_ERROR(&msm_host->pdev->dev, "DSI does not support bits_per_component != 8 yet\n"); + return -EOPNOTSUPP; + } + dsc->rc_model_size = 8192; dsc->first_line_bpg_offset = 12; dsc->rc_edge_factor = 6; -- 2.35.1