From patchwork Tue Feb 23 15:03:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jyri Sarha X-Patchwork-Id: 8393301 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id B78CB9F52D for ; Tue, 23 Feb 2016 15:04:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 44A632034E for ; Tue, 23 Feb 2016 15:04:05 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 5196120303 for ; Tue, 23 Feb 2016 15:04:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 68D1C6E5DE; Tue, 23 Feb 2016 15:04:01 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from arroyo.ext.ti.com (arroyo.ext.ti.com [192.94.94.40]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5F6596E5DD for ; Tue, 23 Feb 2016 15:03:50 +0000 (UTC) Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id u1NF3hpI031978; Tue, 23 Feb 2016 09:03:43 -0600 Received: from DLEE71.ent.ti.com (dlee71.ent.ti.com [157.170.170.114]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id u1NF3h85014725; Tue, 23 Feb 2016 09:03:43 -0600 Received: from dlep33.itg.ti.com (157.170.170.75) by DLEE71.ent.ti.com (157.170.170.114) with Microsoft SMTP Server id 14.3.224.2; Tue, 23 Feb 2016 09:03:43 -0600 Received: from imryr.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dlep33.itg.ti.com (8.14.3/8.13.8) with ESMTP id u1NF3WQY022765; Tue, 23 Feb 2016 09:03:41 -0600 From: Jyri Sarha To: Subject: [PATCH v3 04/22] drm/tilcdc: fix kernel panic on suspend when no hdmi monitor connected Date: Tue, 23 Feb 2016 17:03:12 +0200 Message-ID: X-Mailer: git-send-email 1.9.1 In-Reply-To: References: MIME-Version: 1.0 Cc: Jyri Sarha , Darren Etheridge , tomi.valkeinen@ti.com, laurent.pinchart@ideasonboard.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 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" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Darren Etheridge On BeagleBone Black if no HDMI monitor is connected and suspend is requested a kernel panic will result: root@am335x-evm:~# echo mem > /sys/power/state [ 65.548710] PM: Syncing filesystems ... done. [ 65.631311] Freezing user space processes ... (elapsed 0.006 seconds) done. [ 65.648619] Freezing remaining freezable tasks ... (elapsed 0.005 seconds) done. [ 65.833500] Unhandled fault: external abort on non-linefetch (0x1028) at 0xfa30e004 [ 65.841692] Internal error: : 1028 [#1] SMP ARM [ 66.105287] [] (platform_pm_suspend) from [] (dpm_run_callback+0x34/0x70) [ 66.114370] [] (dpm_run_callback) from [] (__device_suspend+0x10c/0x2f4) [ 66.123357] [] (__device_suspend) from [] (dpm_suspend+0x58/0x218) [ 66.131796] [] (dpm_suspend) from [] (suspend_devices_and_enter+0x9c/0x3c0) [ 66.141055] [] (suspend_devices_and_enter) from [] (pm_suspend+0x210/0x24c) [ 66.150312] [] (pm_suspend) from [] (state_store+0x68/0xb8) [ 66.158103] [] (state_store) from [] (kobj_attr_store+0x14/0x20) [ 66.166355] [] (kobj_attr_store) from [] (sysfs_kf_write+0x4c/0x50) [ 66.174883] [] (sysfs_kf_write) from [] (kernfs_fop_write+0xb4/0x150) [ 66.183598] [] (kernfs_fop_write) from [] (vfs_write+0xa8/0x180) [ 66.191846] [] (vfs_write) from [] (SyS_write+0x40/0x8c) [ 66.199365] [] (SyS_write) from [] (ret_fast_syscall+0x0/0x48) [ 66.207426] Code: e595c210 e5932000 e59cc000 e08c2002 (e592c000) This is because the lcdc module is not enabled when no monitor is detected to save power. However the suspend handler just blindly tries to save the lcdc state by copying out the pertinent registers. However module is off so no good things happen when you try and access it. This patch only saves off the registers if the module is enabled, and then only restores the registers on resume if they were saved off during suspend. Signed-off-by: Darren Etheridge Tested-by: Dave Gerlach Acked-by: Felipe Balbi Signed-off-by: Jyri Sarha --- drivers/gpu/drm/tilcdc/tilcdc_drv.c | 23 +++++++++++++++++------ drivers/gpu/drm/tilcdc/tilcdc_drv.h | 1 + 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c index 420a237..67ed9f7 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c @@ -582,13 +582,20 @@ static int tilcdc_pm_suspend(struct device *dev) drm_kms_helper_poll_disable(ddev); + /* Select sleep pin state */ + pinctrl_pm_select_sleep_state(dev); + + if (pm_runtime_suspended(dev)) { + priv->ctx_valid = false; + return 0; + } + /* Save register state: */ for (i = 0; i < ARRAY_SIZE(registers); i++) if (registers[i].save && (priv->rev >= registers[i].rev)) priv->saved_register[n++] = tilcdc_read(ddev, registers[i].reg); - /* Select sleep pin state */ - pinctrl_pm_select_sleep_state(dev); + priv->ctx_valid = true; return 0; } @@ -602,10 +609,14 @@ static int tilcdc_pm_resume(struct device *dev) /* Select default pin state */ pinctrl_pm_select_default_state(dev); - /* Restore register state: */ - for (i = 0; i < ARRAY_SIZE(registers); i++) - if (registers[i].save && (priv->rev >= registers[i].rev)) - tilcdc_write(ddev, registers[i].reg, priv->saved_register[n++]); + if (priv->ctx_valid == true) { + /* Restore register state: */ + for (i = 0; i < ARRAY_SIZE(registers); i++) + if (registers[i].save && + (priv->rev >= registers[i].rev)) + tilcdc_write(ddev, registers[i].reg, + priv->saved_register[n++]); + } drm_kms_helper_poll_enable(ddev); diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.h b/drivers/gpu/drm/tilcdc/tilcdc_drv.h index 62a1d68..55d17b3 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.h +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.h @@ -67,6 +67,7 @@ struct tilcdc_drm_private { /* register contents saved across suspend/resume: */ u32 saved_register[12]; + bool ctx_valid; #ifdef CONFIG_CPU_FREQ struct notifier_block freq_transition;