From patchwork Thu Feb 4 09:30:58 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jyri Sarha X-Patchwork-Id: 61166 Delivered-To: patch@linaro.org Received: by 10.112.43.199 with SMTP id y7csp348671lbl; Thu, 4 Feb 2016 01:31:42 -0800 (PST) X-Received: by 10.66.191.104 with SMTP id gx8mr9394216pac.21.1454578296132; Thu, 04 Feb 2016 01:31:36 -0800 (PST) Return-Path: Received: from gabe.freedesktop.org (gabe.freedesktop.org. [131.252.210.177]) by mx.google.com with ESMTP id o4si15622639pfo.19.2016.02.04.01.31.35; Thu, 04 Feb 2016 01:31:36 -0800 (PST) Received-SPF: pass (google.com: domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) client-ip=131.252.210.177; Authentication-Results: mx.google.com; spf=pass (google.com: domain of dri-devel-bounces@lists.freedesktop.org designates 131.252.210.177 as permitted sender) smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id ED5296E833; Thu, 4 Feb 2016 01:31:34 -0800 (PST) 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 C6FB86E834 for ; Thu, 4 Feb 2016 01:31:32 -0800 (PST) Received: from dflxv15.itg.ti.com ([128.247.5.124]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id u149VTiU032609; Thu, 4 Feb 2016 03:31:29 -0600 Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id u149VTCs024485; Thu, 4 Feb 2016 03:31:29 -0600 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.224.2; Thu, 4 Feb 2016 03:31:29 -0600 Received: from imryr.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id u149VGFQ011930; Thu, 4 Feb 2016 03:31:27 -0600 From: Jyri Sarha To: Subject: [PATCH 05/21] drm/tilcdc: fix kernel panic on suspend when no hdmi monitor connected Date: Thu, 4 Feb 2016 11:30:58 +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" 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 e25db59..188c3ce 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c @@ -598,13 +598,20 @@ 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; } @@ -618,10 +625,14 @@ 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 c00f518..7d214cc 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;