From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21F5DC4360C for ; Sun, 6 Oct 2019 14:45:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED60620835 for ; Sun, 6 Oct 2019 14:45:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726532AbfJFOp1 (ORCPT ); Sun, 6 Oct 2019 10:45:27 -0400 Received: from hermes.aosc.io ([199.195.250.187]:44891 "EHLO hermes.aosc.io" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725905AbfJFOp0 (ORCPT ); Sun, 6 Oct 2019 10:45:26 -0400 Received: from localhost (localhost [127.0.0.1]) (Authenticated sender: icenowy@aosc.io) by hermes.aosc.io (Postfix) with ESMTPSA id 26B0482916; Sun, 6 Oct 2019 14:45:19 +0000 (UTC) Message-ID: <58dc94b6371ab2f5b11b13ab707d73ab3fc4cc64.camel@aosc.io> Subject: Re: [linux-sunxi] [PATCH 3/3] Revert "drm/sun4i: dsi: Rework a bit the hblk calculation" From: Icenowy Zheng To: Jagan Teki Cc: Maxime Ripard , Chen-Yu Tsai , David Airlie , Daniel Vetter , dri-devel , linux-arm-kernel , linux-kernel , linux-sunxi Date: Sun, 06 Oct 2019 22:44:25 +0800 In-Reply-To: References: <20191001080253.6135-1-icenowy@aosc.io> <20191001080253.6135-4-icenowy@aosc.io> Organization: Anthon Open-Source Community Content-Type: text/plain; charset="UTF-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2019-10-03四的 09:53 +0530，Jagan Teki写道： > Hi Wens, > > On Tue, Oct 1, 2019 at 1:34 PM Icenowy Zheng wrote: > > This reverts commit 62e7511a4f4dcf07f753893d3424decd9466c98b. > > > > This commit, although claimed as a refactor, in fact changed the > > formula. > > > > By expanding the original formula, we can find that the const 10 is > > not > > substracted, instead it's added to the value (because 10 is > > negative > > when calculating hsa, and hsa itself is negative when calculating > > hblk). > > This breaks the similar pattern to other formulas, so restoring the > > original formula is more proper. > > > > Signed-off-by: Icenowy Zheng > > --- > > drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 9 ++------- > > 1 file changed, 2 insertions(+), 7 deletions(-) > > > > diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > index 2d3e822a7739..cb5fd19c0d0d 100644 > > --- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > +++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c > > @@ -577,14 +577,9 @@ static void sun6i_dsi_setup_timings(struct > > sun6i_dsi *dsi, > > (mode->hsync_start - mode->hdisplay) * > > Bpp - HFP_PACKET_OVERHEAD); > > > > /* > > - * The blanking is set using a sync event (4 bytes) > > - * and a blanking packet (4 bytes + payload + 2 > > - * bytes). Its minimal size is therefore 10 bytes. > > + * hblk seems to be the line + porches length. > > */ > > -#define HBLK_PACKET_OVERHEAD 10 > > - hblk = max((unsigned int)HBLK_PACKET_OVERHEAD, > > - (mode->htotal - (mode->hsync_end - mode- > > >hsync_start)) * Bpp - > > - HBLK_PACKET_OVERHEAD); > > + hblk = mode->htotal * Bpp - hsa; > > The original formula is correct according to BSP [1] and work with my > panels which I have tested before. May be the horizontal timings on > panels you have leads to negative value. Do you tested the same timing with BSP kernel? It's quite difficult to get a negative value here, because the value is quite big (includes mode->hdisplay * Bpp). Strangely, only change the formula here back makes the timing translated from FEX file works (tested on PineTab and PinePhone production ver). The translation rule is from [1]. So I still insist on the patch because it's needed by experiment. [1] http://linux-sunxi.org/LCD > > [1] > https://github.com/ayufan-pine64/linux-pine64/blob/my-hacks-1.2-with-drm/drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c#L919