From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B63A030276A; Tue, 31 Mar 2026 17:03:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976592; cv=none; b=hKyHfI6wR+cYsd1IMxwh+JtstbDbLdHX3PDOfN5BDcPw3bvzJPTBwS6cWqqklgWuqlwC05TtKjiSIQjze4WuhNuUjygj2bkXN6teoUfjsVBnQUKYEnULRYO9uZcXtNREatqvayT7ENDAzUkr234TT2qkiJSvK1Z/9yKoFvyOtsc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976592; c=relaxed/simple; bh=pNZ0HtRqKzIjsQruSmSz+1pY8JbRRc6QJkC/dDxtUa4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cQLeJeZaLhdK945bMG1yLLy8OQLpvFeY0tmloO7akcqgTugf/FCp1cAMDt62s5Vl5186D6UFUJ1YbAY7GBkOOf0Qr/O8lhgqaRan20nwheK0U9lanvVo1/KZmbHuVWBP+wmgwb0xEXSUJUdRIJZx6PLRCGPyQKVBhPHyDbgeuxc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tVB3tE/0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="tVB3tE/0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48E0AC19423; Tue, 31 Mar 2026 17:03:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976592; bh=pNZ0HtRqKzIjsQruSmSz+1pY8JbRRc6QJkC/dDxtUa4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tVB3tE/01EZEGXbazSmqKr9mS+bj1NfWuovy+caqLZ5qBpQOD7OMQoCnQ2l7IYsz3 xb2SLEsp3auPOYkYpmNJzdrDNKY014HU3TyGPBle3h82Ro1ZIdiOLWUJDlTJ/lVPBC U87ITmrj4BYonxdi7QU0NhnghGG3HBKx7Zq8h0IU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Luca Leonardo Scorcia , AngeloGioacchino Del Regno , CK Hu , Chun-Kuang Hu , Sasha Levin Subject: [PATCH 6.18 152/309] drm/mediatek: dsi: Store driver data before invoking mipi_dsi_host_register Date: Tue, 31 Mar 2026 18:20:55 +0200 Message-ID: <20260331161759.064038005@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161753.468533260@linuxfoundation.org> References: <20260331161753.468533260@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Luca Leonardo Scorcia [ Upstream commit 4cfdfeb6ac06079f92fccd977fa742d6c5b8dd3a ] The call to mipi_dsi_host_register triggers a callback to mtk_dsi_bind, which uses dev_get_drvdata to retrieve the mtk_dsi struct, so this structure needs to be stored inside the driver data before invoking it. As drvdata is currently uninitialized it leads to a crash when registering the DSI DRM encoder right after acquiring the mode_config.idr_mutex, blocking all subsequent DRM operations. Fixes the following crash during mediatek-drm probe (tested on Xiaomi Smart Clock x04g): Unable to handle kernel NULL pointer dereference at virtual address 0000000000000040 [...] Modules linked in: mediatek_drm(+) drm_display_helper cec drm_client_lib drm_dma_helper drm_kms_helper panel_simple [...] Call trace: drm_mode_object_add+0x58/0x98 (P) __drm_encoder_init+0x48/0x140 drm_encoder_init+0x6c/0xa0 drm_simple_encoder_init+0x20/0x34 [drm_kms_helper] mtk_dsi_bind+0x34/0x13c [mediatek_drm] component_bind_all+0x120/0x280 mtk_drm_bind+0x284/0x67c [mediatek_drm] try_to_bring_up_aggregate_device+0x23c/0x320 __component_add+0xa4/0x198 component_add+0x14/0x20 mtk_dsi_host_attach+0x78/0x100 [mediatek_drm] mipi_dsi_attach+0x2c/0x50 panel_simple_dsi_probe+0x4c/0x9c [panel_simple] mipi_dsi_drv_probe+0x1c/0x28 really_probe+0xc0/0x3dc __driver_probe_device+0x80/0x160 driver_probe_device+0x40/0x120 __device_attach_driver+0xbc/0x17c bus_for_each_drv+0x88/0xf0 __device_attach+0x9c/0x1cc device_initial_probe+0x54/0x60 bus_probe_device+0x34/0xa0 device_add+0x5b0/0x800 mipi_dsi_device_register_full+0xdc/0x16c mipi_dsi_host_register+0xc4/0x17c mtk_dsi_probe+0x10c/0x260 [mediatek_drm] platform_probe+0x5c/0xa4 really_probe+0xc0/0x3dc __driver_probe_device+0x80/0x160 driver_probe_device+0x40/0x120 __driver_attach+0xc8/0x1f8 bus_for_each_dev+0x7c/0xe0 driver_attach+0x24/0x30 bus_add_driver+0x11c/0x240 driver_register+0x68/0x130 __platform_register_drivers+0x64/0x160 mtk_drm_init+0x24/0x1000 [mediatek_drm] do_one_initcall+0x60/0x1d0 do_init_module+0x54/0x240 load_module+0x1838/0x1dc0 init_module_from_file+0xd8/0xf0 __arm64_sys_finit_module+0x1b4/0x428 invoke_syscall.constprop.0+0x48/0xc8 do_el0_svc+0x3c/0xb8 el0_svc+0x34/0xe8 el0t_64_sync_handler+0xa0/0xe4 el0t_64_sync+0x198/0x19c Code: 52800022 941004ab 2a0003f3 37f80040 (29005a80) Fixes: e4732b590a77 ("drm/mediatek: dsi: Register DSI host after acquiring clocks and PHY") Signed-off-by: Luca Leonardo Scorcia Reviewed-by: AngeloGioacchino Del Regno Reviewed-by: CK Hu Link: https://patchwork.kernel.org/project/dri-devel/patch/20260225094047.76780-1-l.scorcia@gmail.com/ Signed-off-by: Chun-Kuang Hu Signed-off-by: Sasha Levin --- drivers/gpu/drm/mediatek/mtk_dsi.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index d7726091819c4..acee2227275b7 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -1232,6 +1232,11 @@ static int mtk_dsi_probe(struct platform_device *pdev) dsi->host.ops = &mtk_dsi_ops; dsi->host.dev = dev; + + init_waitqueue_head(&dsi->irq_wait_queue); + + platform_set_drvdata(pdev, dsi); + ret = mipi_dsi_host_register(&dsi->host); if (ret < 0) return dev_err_probe(dev, ret, "Failed to register DSI host\n"); @@ -1243,10 +1248,6 @@ static int mtk_dsi_probe(struct platform_device *pdev) return dev_err_probe(&pdev->dev, ret, "Failed to request DSI irq\n"); } - init_waitqueue_head(&dsi->irq_wait_queue); - - platform_set_drvdata(pdev, dsi); - dsi->bridge.of_node = dev->of_node; dsi->bridge.type = DRM_MODE_CONNECTOR_DSI; -- 2.53.0