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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 569A0C433EF for ; Thu, 21 Apr 2022 16:33:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229935AbiDUQgL (ORCPT ); Thu, 21 Apr 2022 12:36:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49822 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230172AbiDUQgK (ORCPT ); Thu, 21 Apr 2022 12:36:10 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 409CE2623 for ; Thu, 21 Apr 2022 09:33:20 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 9983C492; Thu, 21 Apr 2022 18:33:17 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1650558797; bh=AauU9WrhhXKScaTW7AXxEi8Y94P2YaLkB6BMWmhdKhE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=morH0nAoZec7svutx3+tJyN2p220P++lm7hFZ5aO/FAoKCACrQaySbTc4YOD3Qr3z 8EtY4U0YG1/+tpU1rEgZqdLkvrkpCDMjvNfhKUevyS4CfFZEIzZ8Ka9IKrCBN8udNI acHwKK2vVCldK6H4IHgduKKzAin4FzFTJ7rxMqMs= Date: Thu, 21 Apr 2022 19:33:18 +0300 From: Laurent Pinchart To: Eugeniu Rosca Cc: Ulrich Hecht , linux-renesas-soc@vger.kernel.org, geert@linux-m68k.org, kuninori.morimoto.gx@renesas.com, dri-devel@lists.freedesktop.org, architt@codeaurora.org, vz@mleia.com, koji.matsuoka.xm@renesas.com, Takashi Saito , Geert Uytterhoeven , Michael Rodin , Eugeniu Rosca Subject: Re: [RFC 14/21] v4l: vsp1: Change VSP1 LIF linebuffer FIFO Message-ID: References: <1464624020-27709-1-git-send-email-ulrich.hecht+renesas@gmail.com> <1464624020-27709-15-git-send-email-ulrich.hecht+renesas@gmail.com> <20220421161259.GA2660@lxhi-065> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220421161259.GA2660@lxhi-065> Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Hi Eugeniu, On Thu, Apr 21, 2022 at 06:12:59PM +0200, Eugeniu Rosca wrote: > Dear Uli, > Dear Laurent, > Dear Renesas community, > > On Mo, Mai 30, 2016 at 06:00:13 +0200, Ulrich Hecht wrote: > > This patch changes to VSPD hardware recommended value. > > Purpose is highest pixel clock without underruns. > > In the default R-Car Linux BSP config this value is > > wrong and therefore there are many underruns. > > > > Signed-off-by: Takashi Saito > > Signed-off-by: Koji Matsuoka > > Signed-off-by: Ulrich Hecht > > Signed-off-by: Geert Uytterhoeven > > --- > > drivers/media/platform/vsp1/vsp1_lif.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > Apologize for reviving this very old thread. > > We've been struggling with very rare and difficult to reproduce > display flickering occurrences and, after significant amount of > troubleshooting and debugging, with some support from Renesas, > we've been able to identify that those flicker issues are caused > by VSPD underruns. > > What we've also learned is that one possible root-cause for seeing > VSPD underruns is having wrong QoS settings in DBSC (set in ATF). > > What was particularly helpful in identifying the underruns themselves > is Renesas BSP commit [1], whose discussions we were unable to track > on linux-renesas-soc LKML. > > My question is very simple. Since the meat of the Renesas patch [1] > is basically a printk in the interrupt context and an array storing > the total number of underruns occurred since startup, would you be > willing to review the refactored version of this patch on LKML? > > In that case, we'll definitely invest some time to upstream it. Absolutely ! I'm all for helping debugging. > Thank you for your attention and feedback. > > [1] https://github.com/renesas-rcar/linux-bsp/commit/12ea79975a10f > ("v4l: vsp1: Add underrun debug messege option") -- Regards, Laurent Pinchart 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 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 C7237C433F5 for ; Thu, 21 Apr 2022 16:33:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id E6EF910E2F4; Thu, 21 Apr 2022 16:33:21 +0000 (UTC) Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by gabe.freedesktop.org (Postfix) with ESMTPS id 96CE510E2F4 for ; Thu, 21 Apr 2022 16:33:19 +0000 (UTC) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 9983C492; Thu, 21 Apr 2022 18:33:17 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1650558797; bh=AauU9WrhhXKScaTW7AXxEi8Y94P2YaLkB6BMWmhdKhE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=morH0nAoZec7svutx3+tJyN2p220P++lm7hFZ5aO/FAoKCACrQaySbTc4YOD3Qr3z 8EtY4U0YG1/+tpU1rEgZqdLkvrkpCDMjvNfhKUevyS4CfFZEIzZ8Ka9IKrCBN8udNI acHwKK2vVCldK6H4IHgduKKzAin4FzFTJ7rxMqMs= Date: Thu, 21 Apr 2022 19:33:18 +0300 From: Laurent Pinchart To: Eugeniu Rosca Subject: Re: [RFC 14/21] v4l: vsp1: Change VSP1 LIF linebuffer FIFO Message-ID: References: <1464624020-27709-1-git-send-email-ulrich.hecht+renesas@gmail.com> <1464624020-27709-15-git-send-email-ulrich.hecht+renesas@gmail.com> <20220421161259.GA2660@lxhi-065> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220421161259.GA2660@lxhi-065> 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: architt@codeaurora.org, Takashi Saito , Geert Uytterhoeven , kuninori.morimoto.gx@renesas.com, Eugeniu Rosca , Michael Rodin , koji.matsuoka.xm@renesas.com, dri-devel@lists.freedesktop.org, vz@mleia.com, linux-renesas-soc@vger.kernel.org, geert@linux-m68k.org, Ulrich Hecht Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Eugeniu, On Thu, Apr 21, 2022 at 06:12:59PM +0200, Eugeniu Rosca wrote: > Dear Uli, > Dear Laurent, > Dear Renesas community, > > On Mo, Mai 30, 2016 at 06:00:13 +0200, Ulrich Hecht wrote: > > This patch changes to VSPD hardware recommended value. > > Purpose is highest pixel clock without underruns. > > In the default R-Car Linux BSP config this value is > > wrong and therefore there are many underruns. > > > > Signed-off-by: Takashi Saito > > Signed-off-by: Koji Matsuoka > > Signed-off-by: Ulrich Hecht > > Signed-off-by: Geert Uytterhoeven > > --- > > drivers/media/platform/vsp1/vsp1_lif.c | 6 +++--- > > 1 file changed, 3 insertions(+), 3 deletions(-) > > Apologize for reviving this very old thread. > > We've been struggling with very rare and difficult to reproduce > display flickering occurrences and, after significant amount of > troubleshooting and debugging, with some support from Renesas, > we've been able to identify that those flicker issues are caused > by VSPD underruns. > > What we've also learned is that one possible root-cause for seeing > VSPD underruns is having wrong QoS settings in DBSC (set in ATF). > > What was particularly helpful in identifying the underruns themselves > is Renesas BSP commit [1], whose discussions we were unable to track > on linux-renesas-soc LKML. > > My question is very simple. Since the meat of the Renesas patch [1] > is basically a printk in the interrupt context and an array storing > the total number of underruns occurred since startup, would you be > willing to review the refactored version of this patch on LKML? > > In that case, we'll definitely invest some time to upstream it. Absolutely ! I'm all for helping debugging. > Thank you for your attention and feedback. > > [1] https://github.com/renesas-rcar/linux-bsp/commit/12ea79975a10f > ("v4l: vsp1: Add underrun debug messege option") -- Regards, Laurent Pinchart