From patchwork Tue Aug 9 00:35:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Abhinav Kumar X-Patchwork-Id: 12939270 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 ABE79C00140 for ; Tue, 9 Aug 2022 00:36:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7E3E4B1F08; Tue, 9 Aug 2022 00:36:01 +0000 (UTC) Received: from alexa-out-sd-01.qualcomm.com (alexa-out-sd-01.qualcomm.com [199.106.114.38]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0B8B2894DE; Tue, 9 Aug 2022 00:35:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; i=@quicinc.com; q=dns/txt; s=qcdkim; t=1660005350; x=1691541350; h=from:to:cc:subject:date:message-id:mime-version; bh=goiRTVR0dzxVxPapYCEI6HEmKLjl86equcMUtqPjUVI=; b=InUVNooslcH/m2QbGvH7Z+6+KVg7z97J/ex792rktZb6gf4BL4FvpkYZ xm7lSGvqsp7/GmfL6U4QElnw/9uWzP26AwjSjgLHqHIuXs9PNSTRimu+e dwNVL5qasC7ueCANJBNKZy8FT+OeygP/hNvqquRV6/LrxY9duVnkhTtWY Q=; Received: from unknown (HELO ironmsg01-sd.qualcomm.com) ([10.53.140.141]) by alexa-out-sd-01.qualcomm.com with ESMTP; 08 Aug 2022 17:35:49 -0700 X-QCInternal: smtphost Received: from nasanex01c.na.qualcomm.com ([10.47.97.222]) by ironmsg01-sd.qualcomm.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Aug 2022 17:35:49 -0700 Received: from nalasex01a.na.qualcomm.com (10.47.209.196) by nasanex01c.na.qualcomm.com (10.47.97.222) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Mon, 8 Aug 2022 17:35:48 -0700 Received: from abhinavk-linux.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.22; Mon, 8 Aug 2022 17:35:47 -0700 From: Abhinav Kumar To: Subject: [RFC] drm/bridge: adv7533: remove dynamic lane switching from adv7533 bridge Date: Mon, 8 Aug 2022 17:35:30 -0700 Message-ID: <1660005330-12369-1-git-send-email-quic_abhinavk@quicinc.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01a.na.qualcomm.com (10.52.223.231) To nalasex01a.na.qualcomm.com (10.47.209.196) 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: jernej.skrabec@gmail.com, andrzej.hajda@intel.com, narmstrong@baylibre.com, airlied@linux.ie, sam@ravnborg.org, jonas@kwiboo.se, Abhinav Kumar , robert.foss@linaro.org, swboyd@chromium.org, seanpaul@chromium.org, Laurent.pinchart@ideasonboard.com, dmitry.baryshkov@linaro.org, quic_jesszhan@quicinc.com, quic_aravindh@quicinc.com, colin.king@intel.com, freedreno@lists.freedesktop.org, maxime@cerno.tech Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" adv7533 bridge tries to dynamically switch lanes based on the mode by detaching and attaching the mipi dsi device. This approach is incorrect because as per the DSI spec the number of lanes is fixed at the time of system design or initial configuration and may not change dynamically. In addition this method of dynamic switch of detaching and attaching the mipi dsi device also results in removing and adding the component which is not necessary. This approach is also prone to deadlocks. So for example, on the db410c whenever this path is executed with lockdep enabled, this results in a deadlock due to below ordering of locks. -> #1 (crtc_ww_class_acquire){+.+.}-{0:0}: lock_acquire+0x6c/0x90 drm_modeset_acquire_init+0xf4/0x150 drmm_mode_config_init+0x220/0x770 msm_drm_bind+0x13c/0x654 try_to_bring_up_aggregate_device+0x164/0x1d0 __component_add+0xa8/0x174 component_add+0x18/0x2c dsi_dev_attach+0x24/0x30 dsi_host_attach+0x98/0x14c devm_mipi_dsi_attach+0x38/0xb0 adv7533_attach_dsi+0x8c/0x110 adv7511_probe+0x5a0/0x930 i2c_device_probe+0x30c/0x350 really_probe.part.0+0x9c/0x2b0 __driver_probe_device+0x98/0x144 driver_probe_device+0xac/0x14c __device_attach_driver+0xbc/0x124 bus_for_each_drv+0x78/0xd0 __device_attach+0xa8/0x1c0 device_initial_probe+0x18/0x24 bus_probe_device+0xa0/0xac deferred_probe_work_func+0x90/0xd0 process_one_work+0x28c/0x6b0 worker_thread+0x240/0x444 kthread+0x110/0x114 ret_from_fork+0x10/0x20 -> #0 (component_mutex){+.+.}-{3:3}: __lock_acquire+0x1280/0x20ac lock_acquire.part.0+0xe0/0x230 lock_acquire+0x6c/0x90 __mutex_lock+0x84/0x400 mutex_lock_nested+0x3c/0x70 component_del+0x34/0x170 dsi_dev_detach+0x24/0x30 dsi_host_detach+0x20/0x64 mipi_dsi_detach+0x2c/0x40 adv7533_mode_set+0x64/0x90 adv7511_bridge_mode_set+0x210/0x214 drm_bridge_chain_mode_set+0x5c/0x84 crtc_set_mode+0x18c/0x1dc drm_atomic_helper_commit_modeset_disables+0x40/0x50 msm_atomic_commit_tail+0x1d0/0x6e0 commit_tail+0xa4/0x180 drm_atomic_helper_commit+0x178/0x3b0 drm_atomic_commit+0xa4/0xe0 drm_client_modeset_commit_atomic+0x228/0x284 drm_client_modeset_commit_locked+0x64/0x1d0 drm_client_modeset_commit+0x34/0x60 drm_fb_helper_lastclose+0x74/0xcc drm_lastclose+0x3c/0x80 drm_release+0xfc/0x114 __fput+0x70/0x224 ____fput+0x14/0x20 task_work_run+0x88/0x1a0 do_exit+0x350/0xa50 do_group_exit+0x38/0xa4 __wake_up_parent+0x0/0x34 invoke_syscall+0x48/0x114 el0_svc_common.constprop.0+0x60/0x11c do_el0_svc+0x30/0xc0 el0_svc+0x58/0x100 el0t_64_sync_handler+0x1b0/0x1bc el0t_64_sync+0x18c/0x190 Due to above reasons, remove the dynamic lane switching code from adv7533 bridge chip and filter out the modes which would need different number of lanes as compared to the initialization time using the mode_valid callback. Suggested-by: Dmitry Baryshkov Signed-off-by: Abhinav Kumar --- drivers/gpu/drm/bridge/adv7511/adv7511.h | 3 ++- drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 18 ++++++++++++++---- drivers/gpu/drm/bridge/adv7511/adv7533.c | 25 +++++++++++++------------ 3 files changed, 29 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h index 9e3bb8a8ee40..0a7cec80b75d 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h @@ -417,7 +417,8 @@ static inline int adv7511_cec_init(struct device *dev, struct adv7511 *adv7511) void adv7533_dsi_power_on(struct adv7511 *adv); void adv7533_dsi_power_off(struct adv7511 *adv); -void adv7533_mode_set(struct adv7511 *adv, const struct drm_display_mode *mode); +enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, + const struct drm_display_mode *mode); int adv7533_patch_registers(struct adv7511 *adv); int adv7533_patch_cec_registers(struct adv7511 *adv); int adv7533_attach_dsi(struct adv7511 *adv); diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 5bb9300040dd..1115ef9be83c 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c @@ -697,7 +697,7 @@ adv7511_detect(struct adv7511 *adv7511, struct drm_connector *connector) } static enum drm_mode_status adv7511_mode_valid(struct adv7511 *adv7511, - struct drm_display_mode *mode) + const struct drm_display_mode *mode) { if (mode->clock > 165000) return MODE_CLOCK_HIGH; @@ -791,9 +791,6 @@ static void adv7511_mode_set(struct adv7511 *adv7511, regmap_update_bits(adv7511->regmap, 0x17, 0x60, (vsync_polarity << 6) | (hsync_polarity << 5)); - if (adv7511->type == ADV7533 || adv7511->type == ADV7535) - adv7533_mode_set(adv7511, adj_mode); - drm_mode_copy(&adv7511->curr_mode, adj_mode); /* @@ -913,6 +910,18 @@ static void adv7511_bridge_mode_set(struct drm_bridge *bridge, adv7511_mode_set(adv, mode, adj_mode); } +static enum drm_mode_status adv7511_bridge_mode_valid(struct drm_bridge *bridge, + const struct drm_display_info *info, + const struct drm_display_mode *mode) +{ + struct adv7511 *adv = bridge_to_adv7511(bridge); + + if (adv->type == ADV7533 || adv->type == ADV7535) + return adv7533_mode_valid(adv, mode); + else + return adv7511_mode_valid(adv, mode); +} + static int adv7511_bridge_attach(struct drm_bridge *bridge, enum drm_bridge_attach_flags flags) { @@ -960,6 +969,7 @@ static const struct drm_bridge_funcs adv7511_bridge_funcs = { .enable = adv7511_bridge_enable, .disable = adv7511_bridge_disable, .mode_set = adv7511_bridge_mode_set, + .mode_valid = adv7511_bridge_mode_valid, .attach = adv7511_bridge_attach, .detect = adv7511_bridge_detect, .get_edid = adv7511_bridge_get_edid, diff --git a/drivers/gpu/drm/bridge/adv7511/adv7533.c b/drivers/gpu/drm/bridge/adv7511/adv7533.c index ef6270806d1d..4a6d45edf431 100644 --- a/drivers/gpu/drm/bridge/adv7511/adv7533.c +++ b/drivers/gpu/drm/bridge/adv7511/adv7533.c @@ -100,26 +100,27 @@ void adv7533_dsi_power_off(struct adv7511 *adv) regmap_write(adv->regmap_cec, 0x27, 0x0b); } -void adv7533_mode_set(struct adv7511 *adv, const struct drm_display_mode *mode) +enum drm_mode_status adv7533_mode_valid(struct adv7511 *adv, + const struct drm_display_mode *mode) { + int lanes; struct mipi_dsi_device *dsi = adv->dsi; - int lanes, ret; - - if (adv->num_dsi_lanes != 4) - return; if (mode->clock > 80000) lanes = 4; else lanes = 3; - if (lanes != dsi->lanes) { - mipi_dsi_detach(dsi); - dsi->lanes = lanes; - ret = mipi_dsi_attach(dsi); - if (ret) - dev_err(&dsi->dev, "failed to change host lanes\n"); - } + /* + * number of lanes cannot be changed after initialization + * as per section 6.1 of the DSI specification. Hence filter + * out the modes which shall need different number of lanes + * than what was configured in the device tree. + */ + if (lanes != dsi->lanes) + return MODE_BAD; + + return MODE_OK; } int adv7533_patch_registers(struct adv7511 *adv)