From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753131AbdLMCvq (ORCPT ); Tue, 12 Dec 2017 21:51:46 -0500 Received: from omzsmtpe02.verizonbusiness.com ([199.249.25.209]:26245 "EHLO omzsmtpe02.verizonbusiness.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752676AbdLMB4r (ORCPT ); Tue, 12 Dec 2017 20:56:47 -0500 From: alexander.levin@verizon.com Cc: Eric Anholt , alexander.levin@verizon.com X-Host: surveyor.tdc.vzwcorp.com To: "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Subject: [PATCH AUTOSEL for 4.14 58/60] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math. Thread-Topic: [PATCH AUTOSEL for 4.14 58/60] drm/vc4: Avoid using vrefresh==0 mode in DSI htotal math. Thread-Index: AQHTc7Vx207oEJJX1ECfSwMWEEMe5w== Date: Wed, 13 Dec 2017 01:55:25 +0000 Message-ID: <20171213015455.6455-58-alexander.levin@verizon.com> References: <20171213015455.6455-1-alexander.levin@verizon.com> In-Reply-To: <20171213015455.6455-1-alexander.levin@verizon.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-messagesentrepresentingtype: 1 x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [10.144.60.250] Content-Type: text/plain; charset="iso-8859-1" MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by nfs id vBD2ppFU025095 From: Eric Anholt [ Upstream commit af2eca53206c59ce9308a4f5f46c4a104a179b6b ] The incoming mode might have a missing vrefresh field if it came from drmModeSetCrtc(), which the kernel is supposed to calculate using drm_mode_vrefresh(). We could either use that or the adjusted_mode's original vrefresh value. However, we can maintain a more exact vrefresh value (not just the integer approximation), by scaling by the ratio of our clocks. v2: Use math suggested by Andrzej Hajda instead. v3: Simplify math now that adjusted_mode->clock isn't padded. v4: Drop some parens. Signed-off-by: Eric Anholt Link: https://patchwork.freedesktop.org/patch/msgid/20170815234722.20700-2-eric@anholt.net Reviewed-by: Andrzej Hajda Signed-off-by: Sasha Levin --- drivers/gpu/drm/vc4/vc4_dsi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/vc4/vc4_dsi.c b/drivers/gpu/drm/vc4/vc4_dsi.c index d1e0dc908048..04796d7d0fdb 100644 --- a/drivers/gpu/drm/vc4/vc4_dsi.c +++ b/drivers/gpu/drm/vc4/vc4_dsi.c @@ -866,7 +866,8 @@ static bool vc4_dsi_encoder_mode_fixup(struct drm_encoder *encoder, adjusted_mode->clock = pixel_clock_hz / 1000 + 1; /* Given the new pixel clock, adjust HFP to keep vrefresh the same. */ - adjusted_mode->htotal = pixel_clock_hz / (mode->vrefresh * mode->vtotal); + adjusted_mode->htotal = adjusted_mode->clock * mode->htotal / + mode->clock; adjusted_mode->hsync_end += adjusted_mode->htotal - mode->htotal; adjusted_mode->hsync_start += adjusted_mode->htotal - mode->htotal; -- 2.11.0