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 92DADC4332F for ; Fri, 25 Nov 2022 22:14:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229634AbiKYWOX (ORCPT ); Fri, 25 Nov 2022 17:14:23 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229514AbiKYWOW (ORCPT ); Fri, 25 Nov 2022 17:14:22 -0500 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA77242F79 for ; Fri, 25 Nov 2022 14:14:20 -0800 (PST) Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 03B288524A; Fri, 25 Nov 2022 23:14:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1669414458; bh=wI3J0mlr5h+qq2aRWmQ8lPDd3WqWNnKhUjad4gkQv+4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=v5LmsyBCZhT3NDqvIe6FIeMApmcw8c92Z1kPUPf4HCDqjuZXu2O0PuRUkZTL4zGAO wGxlRq5ecxiA8W1efezXOLhyPRJuzsQQNsSnf1d0QLx0WmIphslAFuEfieRZKgBRC1 PQX1P7vfRdhtIUaghK1Et/rp2iGkGWKZ2a/QBWsScUI7PSdJNO6sT8KHMIuzWZZvzx k7XTtGVOxtHbO5KCejhzTWEJ/tChrimfg0+eumoGzbtyzKRlPGz3IVebVkrK06oX60 nxavHkZOYwmRW2vDw6DTunqOAjMmJ8awU5LIGkaFfDO3KqU7p+Qn/BbAt+b7yrQCMh l7Xmi8tdw5TFQ== Message-ID: <58671662-9242-c7ef-53ef-60f9cdc3399a@denx.de> Date: Fri, 25 Nov 2022 23:14:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v8 06/14] drm: bridge: samsung-dsim: Handle proper DSI host initialization Content-Language: en-US To: Jagan Teki Cc: Marek Szyprowski , Andrzej Hajda , Inki Dae , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Frieder Schrempf , Fancy Fang , Tim Harvey , Michael Nazzareno Trimarchi , Adam Ford , Neil Armstrong , Robert Foss , Laurent Pinchart , Tommaso Merciai , Matteo Lisi , dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, NXP Linux Team , linux-amarula References: <20221110183853.3678209-1-jagan@amarulasolutions.com> <20221110183853.3678209-7-jagan@amarulasolutions.com> <04fb17e2-1b55-fbd9-d846-da3e3da4edb8@denx.de> From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On 11/23/22 21:09, Jagan Teki wrote: > On Sat, Nov 19, 2022 at 7:45 PM Marek Vasut wrote: >> >> On 11/17/22 14:04, Marek Szyprowski wrote: >>> On 17.11.2022 05:58, Marek Vasut wrote: >>>> On 11/10/22 19:38, Jagan Teki wrote: >>>>> DSI host initialization handling in previous exynos dsi driver has >>>>> some pitfalls. It initializes the host during host transfer() hook >>>>> that is indeed not the desired call flow for I2C and any other DSI >>>>> configured downstream bridges. >>>>> >>>>> Host transfer() is usually triggered for downstream DSI panels or >>>>> bridges and I2C-configured-DSI bridges miss these host initialization >>>>> as these downstream bridges use bridge operations hooks like pre_enable, >>>>> and enable in order to initialize or set up the host. >>>>> >>>>> This patch is trying to handle the host init handler to satisfy all >>>>> downstream panels and bridges. Added the DSIM_STATE_REINITIALIZED state >>>>> flag to ensure that host init is also done on first cmd transfer, this >>>>> helps existing DSI panels work on exynos platform (form Marek >>>>> Szyprowski). >>>>> >>>>> v8, v7, v6, v5: >>>>> * none >>>>> >>>>> v4: >>>>> * update init handling to ensure host init done on first cmd transfer >>>>> >>>>> v3: >>>>> * none >>>>> >>>>> v2: >>>>> * check initialized state in samsung_dsim_init >>>>> >>>>> v1: >>>>> * keep DSI init in host transfer >>>>> >>>>> Signed-off-by: Marek Szyprowski >>>>> Signed-off-by: Jagan Teki >>>>> --- >>>>> drivers/gpu/drm/bridge/samsung-dsim.c | 25 +++++++++++++++++-------- >>>>> include/drm/bridge/samsung-dsim.h | 5 +++-- >>>>> 2 files changed, 20 insertions(+), 10 deletions(-) >>>>> >>>>> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> b/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> index bb1f45fd5a88..ec7e01ae02ea 100644 >>>>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> @@ -1234,12 +1234,17 @@ static void samsung_dsim_disable_irq(struct >>>>> samsung_dsim *dsi) >>>>> disable_irq(dsi->irq); >>>>> } >>>>> -static int samsung_dsim_init(struct samsung_dsim *dsi) >>>>> +static int samsung_dsim_init(struct samsung_dsim *dsi, unsigned int >>>>> flag) >>>>> { >>>>> const struct samsung_dsim_driver_data *driver_data = >>>>> dsi->driver_data; >>>>> + if (dsi->state & flag) >>>>> + return 0; >>>>> + >>>>> samsung_dsim_reset(dsi); >>>>> - samsung_dsim_enable_irq(dsi); >>>>> + >>>>> + if (!(dsi->state & DSIM_STATE_INITIALIZED)) >>>>> + samsung_dsim_enable_irq(dsi); >>>>> if (driver_data->reg_values[RESET_TYPE] == DSIM_FUNCRST) >>>>> samsung_dsim_enable_lane(dsi, BIT(dsi->lanes) - 1); >>>>> @@ -1250,6 +1255,8 @@ static int samsung_dsim_init(struct >>>>> samsung_dsim *dsi) >>>>> samsung_dsim_set_phy_ctrl(dsi); >>>>> samsung_dsim_init_link(dsi); >>>>> + dsi->state |= flag; >>>>> + >>>>> return 0; >>>>> } >>>>> @@ -1269,6 +1276,10 @@ static void >>>>> samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge, >>>>> } >>>>> dsi->state |= DSIM_STATE_ENABLED; >>>>> + >>>>> + ret = samsung_dsim_init(dsi, DSIM_STATE_INITIALIZED); >>>>> + if (ret) >>>>> + return; >>>>> } >>>>> static void samsung_dsim_atomic_enable(struct drm_bridge *bridge, >>>>> @@ -1458,12 +1469,9 @@ static ssize_t >>>>> samsung_dsim_host_transfer(struct mipi_dsi_host *host, >>>>> if (!(dsi->state & DSIM_STATE_ENABLED)) >>>>> return -EINVAL; >>>>> - if (!(dsi->state & DSIM_STATE_INITIALIZED)) { >>>>> - ret = samsung_dsim_init(dsi); >>>>> - if (ret) >>>>> - return ret; >>>>> - dsi->state |= DSIM_STATE_INITIALIZED; >>>>> - } >>>>> + ret = samsung_dsim_init(dsi, DSIM_STATE_REINITIALIZED); >>>> >>>> This triggers full controller reset and reprogramming upon first >>>> command transfer, is such heavy handed reload really necessary ? >>> >>> Yes it is, otherwise the proper DSI panels doesn't work with Exynos DRM >>> DSI. If this is a real issue for you, then maybe the driver could do the >>> initialization conditionally, in prepare() callback in case of IMX and >>> on the first transfer in case of Exynos? >> >> That's odd , it does actually break panel support for me, without this >> double reset the panel works again. But I have to wonder, why would such >> a full reset be necessary at all , even on the exynos ? > > Is it breaking samsung_dsim_reset from host_transfer? maybe checking > whether a reset is required before calling it might fix the issue. I > agree with double initialization is odd but it seems it is required on > some panels in Exynos, I think tweaking them and adjusting the panel > code might resolve this discrepancy. Can someone provide further details on the exynos problem ? 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 2082BC4167D for ; Fri, 25 Nov 2022 22:14:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 52AB510E027; Fri, 25 Nov 2022 22:14:25 +0000 (UTC) Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) by gabe.freedesktop.org (Postfix) with ESMTPS id 515A710E027 for ; Fri, 25 Nov 2022 22:14:21 +0000 (UTC) Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 03B288524A; Fri, 25 Nov 2022 23:14:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1669414458; bh=wI3J0mlr5h+qq2aRWmQ8lPDd3WqWNnKhUjad4gkQv+4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=v5LmsyBCZhT3NDqvIe6FIeMApmcw8c92Z1kPUPf4HCDqjuZXu2O0PuRUkZTL4zGAO wGxlRq5ecxiA8W1efezXOLhyPRJuzsQQNsSnf1d0QLx0WmIphslAFuEfieRZKgBRC1 PQX1P7vfRdhtIUaghK1Et/rp2iGkGWKZ2a/QBWsScUI7PSdJNO6sT8KHMIuzWZZvzx k7XTtGVOxtHbO5KCejhzTWEJ/tChrimfg0+eumoGzbtyzKRlPGz3IVebVkrK06oX60 nxavHkZOYwmRW2vDw6DTunqOAjMmJ8awU5LIGkaFfDO3KqU7p+Qn/BbAt+b7yrQCMh l7Xmi8tdw5TFQ== Message-ID: <58671662-9242-c7ef-53ef-60f9cdc3399a@denx.de> Date: Fri, 25 Nov 2022 23:14:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v8 06/14] drm: bridge: samsung-dsim: Handle proper DSI host initialization Content-Language: en-US To: Jagan Teki References: <20221110183853.3678209-1-jagan@amarulasolutions.com> <20221110183853.3678209-7-jagan@amarulasolutions.com> <04fb17e2-1b55-fbd9-d846-da3e3da4edb8@denx.de> From: Marek Vasut In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean 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: dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, Laurent Pinchart , Joonyoung Shim , Tommaso Merciai , linux-amarula , Seung-Woo Kim , Neil Armstrong , Frieder Schrempf , Kyungmin Park , Matteo Lisi , Robert Foss , Andrzej Hajda , NXP Linux Team , Fancy Fang , Michael Nazzareno Trimarchi , Adam Ford , linux-arm-kernel@lists.infradead.org, Marek Szyprowski Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On 11/23/22 21:09, Jagan Teki wrote: > On Sat, Nov 19, 2022 at 7:45 PM Marek Vasut wrote: >> >> On 11/17/22 14:04, Marek Szyprowski wrote: >>> On 17.11.2022 05:58, Marek Vasut wrote: >>>> On 11/10/22 19:38, Jagan Teki wrote: >>>>> DSI host initialization handling in previous exynos dsi driver has >>>>> some pitfalls. It initializes the host during host transfer() hook >>>>> that is indeed not the desired call flow for I2C and any other DSI >>>>> configured downstream bridges. >>>>> >>>>> Host transfer() is usually triggered for downstream DSI panels or >>>>> bridges and I2C-configured-DSI bridges miss these host initialization >>>>> as these downstream bridges use bridge operations hooks like pre_enable, >>>>> and enable in order to initialize or set up the host. >>>>> >>>>> This patch is trying to handle the host init handler to satisfy all >>>>> downstream panels and bridges. Added the DSIM_STATE_REINITIALIZED state >>>>> flag to ensure that host init is also done on first cmd transfer, this >>>>> helps existing DSI panels work on exynos platform (form Marek >>>>> Szyprowski). >>>>> >>>>> v8, v7, v6, v5: >>>>> * none >>>>> >>>>> v4: >>>>> * update init handling to ensure host init done on first cmd transfer >>>>> >>>>> v3: >>>>> * none >>>>> >>>>> v2: >>>>> * check initialized state in samsung_dsim_init >>>>> >>>>> v1: >>>>> * keep DSI init in host transfer >>>>> >>>>> Signed-off-by: Marek Szyprowski >>>>> Signed-off-by: Jagan Teki >>>>> --- >>>>> drivers/gpu/drm/bridge/samsung-dsim.c | 25 +++++++++++++++++-------- >>>>> include/drm/bridge/samsung-dsim.h | 5 +++-- >>>>> 2 files changed, 20 insertions(+), 10 deletions(-) >>>>> >>>>> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> b/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> index bb1f45fd5a88..ec7e01ae02ea 100644 >>>>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> @@ -1234,12 +1234,17 @@ static void samsung_dsim_disable_irq(struct >>>>> samsung_dsim *dsi) >>>>> disable_irq(dsi->irq); >>>>> } >>>>> -static int samsung_dsim_init(struct samsung_dsim *dsi) >>>>> +static int samsung_dsim_init(struct samsung_dsim *dsi, unsigned int >>>>> flag) >>>>> { >>>>> const struct samsung_dsim_driver_data *driver_data = >>>>> dsi->driver_data; >>>>> + if (dsi->state & flag) >>>>> + return 0; >>>>> + >>>>> samsung_dsim_reset(dsi); >>>>> - samsung_dsim_enable_irq(dsi); >>>>> + >>>>> + if (!(dsi->state & DSIM_STATE_INITIALIZED)) >>>>> + samsung_dsim_enable_irq(dsi); >>>>> if (driver_data->reg_values[RESET_TYPE] == DSIM_FUNCRST) >>>>> samsung_dsim_enable_lane(dsi, BIT(dsi->lanes) - 1); >>>>> @@ -1250,6 +1255,8 @@ static int samsung_dsim_init(struct >>>>> samsung_dsim *dsi) >>>>> samsung_dsim_set_phy_ctrl(dsi); >>>>> samsung_dsim_init_link(dsi); >>>>> + dsi->state |= flag; >>>>> + >>>>> return 0; >>>>> } >>>>> @@ -1269,6 +1276,10 @@ static void >>>>> samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge, >>>>> } >>>>> dsi->state |= DSIM_STATE_ENABLED; >>>>> + >>>>> + ret = samsung_dsim_init(dsi, DSIM_STATE_INITIALIZED); >>>>> + if (ret) >>>>> + return; >>>>> } >>>>> static void samsung_dsim_atomic_enable(struct drm_bridge *bridge, >>>>> @@ -1458,12 +1469,9 @@ static ssize_t >>>>> samsung_dsim_host_transfer(struct mipi_dsi_host *host, >>>>> if (!(dsi->state & DSIM_STATE_ENABLED)) >>>>> return -EINVAL; >>>>> - if (!(dsi->state & DSIM_STATE_INITIALIZED)) { >>>>> - ret = samsung_dsim_init(dsi); >>>>> - if (ret) >>>>> - return ret; >>>>> - dsi->state |= DSIM_STATE_INITIALIZED; >>>>> - } >>>>> + ret = samsung_dsim_init(dsi, DSIM_STATE_REINITIALIZED); >>>> >>>> This triggers full controller reset and reprogramming upon first >>>> command transfer, is such heavy handed reload really necessary ? >>> >>> Yes it is, otherwise the proper DSI panels doesn't work with Exynos DRM >>> DSI. If this is a real issue for you, then maybe the driver could do the >>> initialization conditionally, in prepare() callback in case of IMX and >>> on the first transfer in case of Exynos? >> >> That's odd , it does actually break panel support for me, without this >> double reset the panel works again. But I have to wonder, why would such >> a full reset be necessary at all , even on the exynos ? > > Is it breaking samsung_dsim_reset from host_transfer? maybe checking > whether a reset is required before calling it might fix the issue. I > agree with double initialization is odd but it seems it is required on > some panels in Exynos, I think tweaking them and adjusting the panel > code might resolve this discrepancy. Can someone provide further details on the exynos problem ? 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 79B88C4332F for ; Fri, 25 Nov 2022 22:15:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IVSumMf0l0NRHDryRkgmOMKxFBEbkyRGwNgv21AJZK0=; b=u1InEPM8fiSo7W YhJsjmJN6oHwW2VG42+mebWHVP5D5nH9oU7QRFtTJUZFD6NJHh7cG8uTtKixKqv2MJVMgTfwyYD53 59cKDar/BQ0H3GYWGvaWHi3SwOyBVFLGjwQvy7QCi27cGWbLBSqgZZbpi3mzP8S8J6Wneb5R8ZbFd gsyRxucGzDcZ4cdRPUPfaRxv9SYrQe8I1jj81IaAN8mucK4vvUp4kYqg24Avlfni0Q3uW6NgMqltD PVNBmBdDPyaIV+a07WFZXL4yw6wm+SUqnAbfx78kdgebzZ+4dAbNbAcbVyv6BpFuqMQxYWSNrIMAa +2CYHvsKhC9KMA3tYi4Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oygxm-002PVS-PW; Fri, 25 Nov 2022 22:14:26 +0000 Received: from phobos.denx.de ([85.214.62.61]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oygxj-002PUi-9V for linux-arm-kernel@lists.infradead.org; Fri, 25 Nov 2022 22:14:25 +0000 Received: from [127.0.0.1] (p578adb1c.dip0.t-ipconnect.de [87.138.219.28]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id 03B288524A; Fri, 25 Nov 2022 23:14:16 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1669414458; bh=wI3J0mlr5h+qq2aRWmQ8lPDd3WqWNnKhUjad4gkQv+4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=v5LmsyBCZhT3NDqvIe6FIeMApmcw8c92Z1kPUPf4HCDqjuZXu2O0PuRUkZTL4zGAO wGxlRq5ecxiA8W1efezXOLhyPRJuzsQQNsSnf1d0QLx0WmIphslAFuEfieRZKgBRC1 PQX1P7vfRdhtIUaghK1Et/rp2iGkGWKZ2a/QBWsScUI7PSdJNO6sT8KHMIuzWZZvzx k7XTtGVOxtHbO5KCejhzTWEJ/tChrimfg0+eumoGzbtyzKRlPGz3IVebVkrK06oX60 nxavHkZOYwmRW2vDw6DTunqOAjMmJ8awU5LIGkaFfDO3KqU7p+Qn/BbAt+b7yrQCMh l7Xmi8tdw5TFQ== Message-ID: <58671662-9242-c7ef-53ef-60f9cdc3399a@denx.de> Date: Fri, 25 Nov 2022 23:14:16 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.5.0 Subject: Re: [PATCH v8 06/14] drm: bridge: samsung-dsim: Handle proper DSI host initialization Content-Language: en-US To: Jagan Teki Cc: Marek Szyprowski , Andrzej Hajda , Inki Dae , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , Frieder Schrempf , Fancy Fang , Tim Harvey , Michael Nazzareno Trimarchi , Adam Ford , Neil Armstrong , Robert Foss , Laurent Pinchart , Tommaso Merciai , Matteo Lisi , dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, NXP Linux Team , linux-amarula References: <20221110183853.3678209-1-jagan@amarulasolutions.com> <20221110183853.3678209-7-jagan@amarulasolutions.com> <04fb17e2-1b55-fbd9-d846-da3e3da4edb8@denx.de> From: Marek Vasut In-Reply-To: X-Virus-Scanned: clamav-milter 0.103.6 at phobos.denx.de X-Virus-Status: Clean X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221125_141423_745694_7EE1A615 X-CRM114-Status: GOOD ( 26.03 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 11/23/22 21:09, Jagan Teki wrote: > On Sat, Nov 19, 2022 at 7:45 PM Marek Vasut wrote: >> >> On 11/17/22 14:04, Marek Szyprowski wrote: >>> On 17.11.2022 05:58, Marek Vasut wrote: >>>> On 11/10/22 19:38, Jagan Teki wrote: >>>>> DSI host initialization handling in previous exynos dsi driver has >>>>> some pitfalls. It initializes the host during host transfer() hook >>>>> that is indeed not the desired call flow for I2C and any other DSI >>>>> configured downstream bridges. >>>>> >>>>> Host transfer() is usually triggered for downstream DSI panels or >>>>> bridges and I2C-configured-DSI bridges miss these host initialization >>>>> as these downstream bridges use bridge operations hooks like pre_enable, >>>>> and enable in order to initialize or set up the host. >>>>> >>>>> This patch is trying to handle the host init handler to satisfy all >>>>> downstream panels and bridges. Added the DSIM_STATE_REINITIALIZED state >>>>> flag to ensure that host init is also done on first cmd transfer, this >>>>> helps existing DSI panels work on exynos platform (form Marek >>>>> Szyprowski). >>>>> >>>>> v8, v7, v6, v5: >>>>> * none >>>>> >>>>> v4: >>>>> * update init handling to ensure host init done on first cmd transfer >>>>> >>>>> v3: >>>>> * none >>>>> >>>>> v2: >>>>> * check initialized state in samsung_dsim_init >>>>> >>>>> v1: >>>>> * keep DSI init in host transfer >>>>> >>>>> Signed-off-by: Marek Szyprowski >>>>> Signed-off-by: Jagan Teki >>>>> --- >>>>> drivers/gpu/drm/bridge/samsung-dsim.c | 25 +++++++++++++++++-------- >>>>> include/drm/bridge/samsung-dsim.h | 5 +++-- >>>>> 2 files changed, 20 insertions(+), 10 deletions(-) >>>>> >>>>> diff --git a/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> b/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> index bb1f45fd5a88..ec7e01ae02ea 100644 >>>>> --- a/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> +++ b/drivers/gpu/drm/bridge/samsung-dsim.c >>>>> @@ -1234,12 +1234,17 @@ static void samsung_dsim_disable_irq(struct >>>>> samsung_dsim *dsi) >>>>> disable_irq(dsi->irq); >>>>> } >>>>> -static int samsung_dsim_init(struct samsung_dsim *dsi) >>>>> +static int samsung_dsim_init(struct samsung_dsim *dsi, unsigned int >>>>> flag) >>>>> { >>>>> const struct samsung_dsim_driver_data *driver_data = >>>>> dsi->driver_data; >>>>> + if (dsi->state & flag) >>>>> + return 0; >>>>> + >>>>> samsung_dsim_reset(dsi); >>>>> - samsung_dsim_enable_irq(dsi); >>>>> + >>>>> + if (!(dsi->state & DSIM_STATE_INITIALIZED)) >>>>> + samsung_dsim_enable_irq(dsi); >>>>> if (driver_data->reg_values[RESET_TYPE] == DSIM_FUNCRST) >>>>> samsung_dsim_enable_lane(dsi, BIT(dsi->lanes) - 1); >>>>> @@ -1250,6 +1255,8 @@ static int samsung_dsim_init(struct >>>>> samsung_dsim *dsi) >>>>> samsung_dsim_set_phy_ctrl(dsi); >>>>> samsung_dsim_init_link(dsi); >>>>> + dsi->state |= flag; >>>>> + >>>>> return 0; >>>>> } >>>>> @@ -1269,6 +1276,10 @@ static void >>>>> samsung_dsim_atomic_pre_enable(struct drm_bridge *bridge, >>>>> } >>>>> dsi->state |= DSIM_STATE_ENABLED; >>>>> + >>>>> + ret = samsung_dsim_init(dsi, DSIM_STATE_INITIALIZED); >>>>> + if (ret) >>>>> + return; >>>>> } >>>>> static void samsung_dsim_atomic_enable(struct drm_bridge *bridge, >>>>> @@ -1458,12 +1469,9 @@ static ssize_t >>>>> samsung_dsim_host_transfer(struct mipi_dsi_host *host, >>>>> if (!(dsi->state & DSIM_STATE_ENABLED)) >>>>> return -EINVAL; >>>>> - if (!(dsi->state & DSIM_STATE_INITIALIZED)) { >>>>> - ret = samsung_dsim_init(dsi); >>>>> - if (ret) >>>>> - return ret; >>>>> - dsi->state |= DSIM_STATE_INITIALIZED; >>>>> - } >>>>> + ret = samsung_dsim_init(dsi, DSIM_STATE_REINITIALIZED); >>>> >>>> This triggers full controller reset and reprogramming upon first >>>> command transfer, is such heavy handed reload really necessary ? >>> >>> Yes it is, otherwise the proper DSI panels doesn't work with Exynos DRM >>> DSI. If this is a real issue for you, then maybe the driver could do the >>> initialization conditionally, in prepare() callback in case of IMX and >>> on the first transfer in case of Exynos? >> >> That's odd , it does actually break panel support for me, without this >> double reset the panel works again. But I have to wonder, why would such >> a full reset be necessary at all , even on the exynos ? > > Is it breaking samsung_dsim_reset from host_transfer? maybe checking > whether a reset is required before calling it might fix the issue. I > agree with double initialization is odd but it seems it is required on > some panels in Exynos, I think tweaking them and adjusting the panel > code might resolve this discrepancy. Can someone provide further details on the exynos problem ? _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel