From patchwork Wed Feb 24 16:48:38 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jyri Sarha X-Patchwork-Id: 62807 Delivered-To: patch@linaro.org Received: by 10.112.43.199 with SMTP id y7csp2513949lbl; Wed, 24 Feb 2016 08:49:19 -0800 (PST) X-Received: by 10.98.93.2 with SMTP id r2mr56347665pfb.64.1456332555329; Wed, 24 Feb 2016 08:49:15 -0800 (PST) Return-Path: Received: from gabe.freedesktop.org (gabe.freedesktop.org. [131.252.210.177]) by mx.google.com with ESMTP id g4si5963807pat.65.2016.02.24.08.49.15; Wed, 24 Feb 2016 08:49:15 -0800 (PST) Received-SPF: pass (google.com: best guess record for 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: best guess record for 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 844ED6E7FA; Wed, 24 Feb 2016 16:49:14 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from bear.ext.ti.com (bear.ext.ti.com [192.94.94.41]) by gabe.freedesktop.org (Postfix) with ESMTPS id 6A1F26E801 for ; Wed, 24 Feb 2016 16:49:13 +0000 (UTC) Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by bear.ext.ti.com (8.13.7/8.13.7) with ESMTP id u1OGn9De027969; Wed, 24 Feb 2016 10:49:09 -0600 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id u1OGn9Dc005679; Wed, 24 Feb 2016 10:49:09 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.3.224.2; Wed, 24 Feb 2016 10:49:09 -0600 Received: from imryr.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id u1OGmwib009536; Wed, 24 Feb 2016 10:49:07 -0600 From: Jyri Sarha To: Subject: [PATCH v4 04/22] drm/tilcdc: fix kernel panic on suspend when no hdmi monitor connected Date: Wed, 24 Feb 2016 18:48:38 +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 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;