From patchwork Sat Oct 1 19:08:03 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marijn Suijten X-Patchwork-Id: 12996668 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 8D4D5C433FE for ; Sat, 1 Oct 2022 19:08:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2D25910E4D0; Sat, 1 Oct 2022 19:08:31 +0000 (UTC) Received: from relay04.th.seeweb.it (relay04.th.seeweb.it [IPv6:2001:4b7a:2000:18::165]) by gabe.freedesktop.org (Postfix) with ESMTPS id D2F4310E08D for ; Sat, 1 Oct 2022 19:08:21 +0000 (UTC) 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-r1.th.seeweb.it (Postfix) with ESMTPSA id BB91F2036C; Sat, 1 Oct 2022 21:08:19 +0200 (CEST) From: Marijn Suijten To: phone-devel@vger.kernel.org, Rob Clark , Dmitry Baryshkov , Vinod Koul Subject: [PATCH 1/5] drm/msm/dsi: Remove useless math in DSC calculation Date: Sat, 1 Oct 2022 21:08:03 +0200 Message-Id: <20221001190807.358691-2-marijn.suijten@somainline.org> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20221001190807.358691-1-marijn.suijten@somainline.org> References: <20221001190807.358691-1-marijn.suijten@somainline.org> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marek Vasut , freedreno@lists.freedesktop.org, Douglas Anderson , Thomas Zimmermann , Jami Kettunen , Vladimir Lypak , linux-arm-msm@vger.kernel.org, Konrad Dybcio , Abhinav Kumar , dri-devel@lists.freedesktop.org, Javier Martinez Canillas , David Airlie , Martin Botka , ~postmarketos/upstreaming@lists.sr.ht, AngeloGioacchino Del Regno , Alex Deucher , Marijn Suijten , Sean Paul , linux-kernel@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Multiplying a value by 2 and adding 1 to it always results in a value that is uneven, and that 1 gets truncated immediately when performing integer division by 2 again. There is no "rounding" possible here. Fixes: b9080324d6ca ("drm/msm/dsi: add support for dsc data") Signed-off-by: Marijn Suijten Reviewed-by: Konrad Dybcio Reviewed-by: Bjorn Andersson --- drivers/gpu/drm/msm/dsi/dsi_host.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c index 8e4bc586c262..e05bae647431 100644 --- a/drivers/gpu/drm/msm/dsi/dsi_host.c +++ b/drivers/gpu/drm/msm/dsi/dsi_host.c @@ -1864,12 +1864,7 @@ static int dsi_populate_dsc_params(struct drm_dsc_config *dsc) data = 2048 * (dsc->rc_model_size - dsc->initial_offset + num_extra_mux_bits); dsc->slice_bpg_offset = DIV_ROUND_UP(data, groups_total); - /* bpp * 16 + 0.5 */ - data = dsc->bits_per_pixel * 16; - data *= 2; - data++; - data /= 2; - target_bpp_x16 = data; + target_bpp_x16 = dsc->bits_per_pixel * 16; data = (dsc->initial_xmit_delay * target_bpp_x16) / 16; final_value = dsc->rc_model_size - data + num_extra_mux_bits;