From nobody Fri Dec 19 01:49:51 2025 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 636A9C83F11 for ; Mon, 28 Aug 2023 16:00:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232599AbjH1P7w (ORCPT ); Mon, 28 Aug 2023 11:59:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58460 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232596AbjH1P7W (ORCPT ); Mon, 28 Aug 2023 11:59:22 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4BCCA123 for ; Mon, 28 Aug 2023 08:59:19 -0700 (PDT) Received: from dude05.red.stw.pengutronix.de ([2a0a:edc0:0:1101:1d::54]) by metis.ext.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1qaee1-0005pk-FX; Mon, 28 Aug 2023 17:59:13 +0200 From: Michael Tretter Date: Mon, 28 Aug 2023 17:59:10 +0200 Subject: [PATCH 5/5] drm/bridge: samsung-dsim: calculate porches in Hz MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20230818-samsung-dsim-v1-5-b39716db6b7a@pengutronix.de> References: <20230818-samsung-dsim-v1-0-b39716db6b7a@pengutronix.de> In-Reply-To: <20230818-samsung-dsim-v1-0-b39716db6b7a@pengutronix.de> To: Inki Dae , Jagan Teki , Marek Szyprowski , Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , David Airlie , Daniel Vetter Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, Michael Tretter X-Mailer: b4 0.12.0 X-SA-Exim-Connect-IP: 2a0a:edc0:0:1101:1d::54 X-SA-Exim-Mail-From: m.tretter@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Calculating the byte_clk in kHz is imprecise for a hs_clock of 55687500 Hz, which may be used with a pixel clock of 74.25 MHz with mode 1920x1080-30. Fix the calculation by using HZ instead of kHZ. This requires to change the type to u64 to prevent overflows of the integer type. Signed-off-by: Michael Tretter Reviewed-by: Adam Ford #imx8mm-beacon Tested-by: Adam Ford #imx8mm-beacon --- drivers/gpu/drm/bridge/samsung-dsim.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c b/drivers/gpu/drm/bridge= /samsung-dsim.c index 459be953be55..eb7aca2b9ab7 100644 --- a/drivers/gpu/drm/bridge/samsung-dsim.c +++ b/drivers/gpu/drm/bridge/samsung-dsim.c @@ -973,10 +973,12 @@ static void samsung_dsim_set_display_mode(struct sams= ung_dsim *dsi) u32 reg; =20 if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) { - int byte_clk_khz =3D dsi->hs_clock / 1000 / 8; - int hfp =3D DIV_ROUND_UP((m->hsync_start - m->hdisplay) * byte_clk_khz, = m->clock); - int hbp =3D DIV_ROUND_UP((m->htotal - m->hsync_end) * byte_clk_khz, m->c= lock); - int hsa =3D DIV_ROUND_UP((m->hsync_end - m->hsync_start) * byte_clk_khz,= m->clock); + u64 byte_clk =3D dsi->hs_clock / 8; + u64 pix_clk =3D m->clock * 1000; + + int hfp =3D DIV64_U64_ROUND_UP((m->hsync_start - m->hdisplay) * byte_clk= , pix_clk); + int hbp =3D DIV64_U64_ROUND_UP((m->htotal - m->hsync_end) * byte_clk, pi= x_clk); + int hsa =3D DIV64_U64_ROUND_UP((m->hsync_end - m->hsync_start) * byte_cl= k, pix_clk); =20 /* remove packet overhead when possible */ hfp =3D max(hfp - 6, 0); --=20 2.39.2