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 5696FC77B7F for ; Tue, 24 Jun 2025 20:15:00 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B0C3E10E035; Tue, 24 Jun 2025 20:14:59 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.b="PUMeLFoW"; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9CE2E10E035 for ; Tue, 24 Jun 2025 20:14:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750796080; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=MpswX9CeYFwqxV2+s21tSoizpPJHKG6Ho7VniV3X4Tw=; b=PUMeLFoW1A6QD8CfJfDJ2KXccMAglobns+Vh7wAJ3sgzFZt5m1dwGplfp1MbFhVJf4drmp x1HCW4rzha9cS/9MZVEuqkC1/J870OPFiiv+BS/rluFuP5m6Tn6lLnjOmC9aFXQMt7Sx0w g+lOSsy/4gsv/uvSl2vJaY8B8fjuWlI= Received: from mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-18-5LbBZxgQPcSwyk4vLV8pZA-1; Tue, 24 Jun 2025 16:14:35 -0400 X-MC-Unique: 5LbBZxgQPcSwyk4vLV8pZA-1 X-Mimecast-MFC-AGG-ID: 5LbBZxgQPcSwyk4vLV8pZA_1750796073 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-04.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 0311A19560B2; Tue, 24 Jun 2025 20:14:33 +0000 (UTC) Received: from asrivats-na.rmtustx.csb (unknown [10.2.16.179]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP id 32307180045B; Tue, 24 Jun 2025 20:14:30 +0000 (UTC) From: Anusha Srivatsa Date: Tue, 24 Jun 2025 15:13:05 -0500 Subject: [PATCH] panel/simple-simple: Identify simple DPI panels using .compatible field MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250624-b4-simple-panel-regression-v1-1-a5adf92a7c17@redhat.com> X-B4-Tracking: v=1; b=H4sIANAGW2gC/x3MQQqDQAxG4atI1g1oqiJepXQx1l8N2OmQgAji3 Tu6/BbvHeQwhVNfHGTY1PUXM6pHQZ8lxBmsYzZJKU3ZSs1Dza7ftIJTiFjZMBv8yrgLeA5BOpk glAfJMOl+z1/v8/wDlerxC2wAAAA= X-Change-ID: 20250624-b4-simple-panel-regression-8ae3ba282fe2 To: Neil Armstrong , Jessica Zhang , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Luca Ceresoli Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Francesco Dolcini , Anusha Srivatsa X-Developer-Signature: v=1; a=ed25519-sha256; t=1750796000; l=7046; i=asrivats@redhat.com; s=20250122; h=from:subject:message-id; bh=kcL0cNSlO6mnJ6CE0453W1DJuh3tCx3/N4e0pmAMZ24=; b=Oync0rm63Wr+egSAoKVm0V/1mZPYmfkM+U8w49SDLCrXNtXYMqaO6Knl/tvZQimVOEqed1E4u CH8Rg+saix/DJnQAnr8fP2t579abWBMlSyOMCS8WAfOsJgs5qRSdxyG X-Developer-Key: i=asrivats@redhat.com; a=ed25519; pk=brnIHkBsUZEhyW6Zyn0U92AeIZ1psws/q8VFbIkf1AU= X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 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: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Currently driver is checking for desc == &panel_dpi to do the DPI specific panel desc allocations. This looks hacky. The panel allocation in panel_simple_probe() breaks due to not having the desc for DPI scenario. This patch does the following: - Rename panel_dpi_probe() to panel_dpi_get_desc() and call it before panel allocation. panel_dpi_get_desc() returns a panel desc unlike panel_dpi_probe() which returned an int. This way driver has a known connector type while allocating the panel. - panel_dpi_get_desc() returns a panel desc - Add a simple helper is_panel_dpi() to identify a simple DPI panel from a simple panel based on .compatible field Fixes: de04bb0089a9 ("drm/panel/panel-simple: Use the new allocation in place of devm_kzalloc()") Suggested-by: Luca Ceresoli Suggested-by: Maxime Ripard Cc: Francesco Dolcini Cc: Luca Ceresoli Cc: Maxime Ripard Signed-off-by: Anusha Srivatsa --- Seeing the below trace due to the changes introduced by: Commit de04bb0089a9 ("drm/panel/panel-simple: Use the new allocation in place of devm_kzalloc()") [ 12.089274] ------------[ cut here ]------------ [ 12.089303] WARNING: CPU: 0 PID: 96 at drivers/gpu/drm/bridge/panel.c:377 devm_drm_of_get_bridge+0xac/0xb8 [ 12.130808] Modules linked in: v4l2_jpeg pwm_imx27(+) imx_vdoa gpu_sched panel_simple imx6_media(C) imx_media_common (C) videobuf2_dma_contig pwm_bl gpio_keys v4l2_mem2mem fuse ipv6 autofs4 [ 12.147774] CPU: 0 UID: 0 PID: 96 Comm: kworker/u8:3 Tainted: G C 6.16.0-rc1+ #1 PREEMPT [ 12.157446] Tainted: [C]=CRAP [ 12.160418] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 12.166953] Workqueue: events_unbound deferred_probe_work_func [ 12.172805] Call trace: [ 12.172815] unwind_backtrace from show_stack+0x10/0x14 [ 12.180598] show_stack from dump_stack_lvl+0x68/0x74 [ 12.185674] dump_stack_lvl from __warn+0x7c/0xe0 [ 12.190407] __warn from warn_slowpath_fmt+0x1b8/0x1c0 [ 12.195567] warn_slowpath_fmt from devm_drm_of_get_bridge+0xac/0xb8 [ 12.201949] devm_drm_of_get_bridge from imx_pd_probe+0x58/0x164 [ 12.207976] imx_pd_probe from platform_probe+0x5c/0xb0 [ 12.213220] platform_probe from really_probe+0xd0/0x3a4 [ 12.218551] really_probe from __driver_probe_device+0x8c/0x1d4 [ 12.224486] __driver_probe_device from driver_probe_device+0x30/0xc0 [ 12.230942] driver_probe_device from __device_attach_driver+0x98/0x10c [ 12.237572] __device_attach_driver from bus_for_each_drv+0x90/0xe4 [ 12.243854] bus_for_each_drv from __device_attach+0xa8/0x1c8 [ 12.249614] __device_attach from bus_probe_device+0x88/0x8c [ 12.255285] bus_probe_device from deferred_probe_work_func+0x8c/0xcc [ 12.261739] deferred_probe_work_func from process_one_work+0x154/0x2dc [ 12.268371] process_one_work from worker_thread+0x250/0x3f0 [ 12.274043] worker_thread from kthread+0x12c/0x24c [ 12.278940] kthread from ret_from_fork+0x14/0x28 [ 12.283660] Exception stack(0xd0be9fb0 to 0xd0be9ff8) [ 12.288720] 9fa0: 00000000 00000000 00000000 00000000 [ 12.296906] 9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 12.305089] 9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 12.312050] ---[ end trace 0000000000000000 ]--- --- drivers/gpu/drm/panel/panel-simple.c | 38 +++++++++++++++++++++--------------- 1 file changed, 22 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c index 0a3b26bb4d731c54614e24e38018c308acd5367a..2e6fd545100388a9d53183a5621e7b8fdb4148ae 100644 --- a/drivers/gpu/drm/panel/panel-simple.c +++ b/drivers/gpu/drm/panel/panel-simple.c @@ -26,6 +26,7 @@ #include #include #include +#include #include #include #include @@ -432,8 +433,7 @@ static const struct drm_panel_funcs panel_simple_funcs = { static struct panel_desc panel_dpi; -static int panel_dpi_probe(struct device *dev, - struct panel_simple *panel) +static struct panel_desc *panel_dpi_get_desc(struct device *dev) { struct display_timing *timing; const struct device_node *np; @@ -445,17 +445,17 @@ static int panel_dpi_probe(struct device *dev, np = dev->of_node; desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL); if (!desc) - return -ENOMEM; + return NULL; timing = devm_kzalloc(dev, sizeof(*timing), GFP_KERNEL); if (!timing) - return -ENOMEM; + return NULL; ret = of_get_display_timing(np, "panel-timing", timing); if (ret < 0) { dev_err(dev, "%pOF: no panel-timing node found for \"panel-dpi\" binding\n", np); - return ret; + return NULL; } desc->timings = timing; @@ -473,9 +473,7 @@ static int panel_dpi_probe(struct device *dev, /* We do not know the connector for the DT node, so guess it */ desc->connector_type = DRM_MODE_CONNECTOR_DPI; - panel->desc = desc; - - return 0; + return desc; } #define PANEL_SIMPLE_BOUNDS_CHECK(to_check, bounds, field) \ @@ -570,6 +568,15 @@ static int panel_simple_override_nondefault_lvds_datamapping(struct device *dev, return 0; } +static bool is_panel_dpi(struct device *dev) +{ + const struct of_device_id *match; + + match = of_match_device(dev->driver->of_match_table, dev); + + return strcmp(match->compatible, "panel_dpi"); +} + static int panel_simple_probe(struct device *dev, const struct panel_desc *desc) { struct panel_simple *panel; @@ -579,6 +586,10 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc) u32 bus_flags; int err; + /* Is this simple panel a DPI panel */ + if (is_panel_dpi(dev)) + desc = panel_dpi_get_desc(dev); + panel = devm_drm_panel_alloc(dev, struct panel_simple, base, &panel_simple_funcs, desc->connector_type); if (IS_ERR(panel)) @@ -611,16 +622,11 @@ static int panel_simple_probe(struct device *dev, const struct panel_desc *desc) return -EPROBE_DEFER; } - if (desc == &panel_dpi) { - /* Handle the generic panel-dpi binding */ - err = panel_dpi_probe(dev, panel); - if (err) - goto free_ddc; - desc = panel->desc; - } else { + if (is_panel_dpi(dev)) + goto free_ddc; + else if (!of_get_display_timing(dev->of_node, "panel-timing", &dt)) panel_simple_parse_panel_timing_node(dev, panel, &dt); - } if (desc->connector_type == DRM_MODE_CONNECTOR_LVDS) { /* Optional data-mapping property for overriding bus format */ --- base-commit: 10357824151262636fda879845f8b64553541106 change-id: 20250624-b4-simple-panel-regression-8ae3ba282fe2 Best regards, -- Anusha Srivatsa