From patchwork Tue Feb 16 14:18:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jyri Sarha X-Patchwork-Id: 62027 Delivered-To: patch@linaro.org Received: by 10.112.43.199 with SMTP id y7csp1691482lbl; Tue, 16 Feb 2016 06:19:01 -0800 (PST) X-Received: by 10.98.65.193 with SMTP id g62mr31363883pfd.148.1455632339474; Tue, 16 Feb 2016 06:18:59 -0800 (PST) Return-Path: Received: from gabe.freedesktop.org (gabe.freedesktop.org. [131.252.210.177]) by mx.google.com with ESMTP id qw9si51488014pab.126.2016.02.16.06.18.59; Tue, 16 Feb 2016 06:18:59 -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 B13C06E7F8; Tue, 16 Feb 2016 14:18:58 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from devils.ext.ti.com (devils.ext.ti.com [198.47.26.153]) by gabe.freedesktop.org (Postfix) with ESMTPS id B59706E7F8 for ; Tue, 16 Feb 2016 14:18:55 +0000 (UTC) Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id u1GEIqVv017719; Tue, 16 Feb 2016 08:18:52 -0600 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id u1GEIqfC031833; Tue, 16 Feb 2016 08:18:52 -0600 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.224.2; Tue, 16 Feb 2016 08:18:52 -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 u1GEIftN011585; Tue, 16 Feb 2016 08:18:50 -0600 From: Jyri Sarha To: Subject: [PATCH v2 04/21] drm/tilcdc: fix kernel panic on suspend when no hdmi monitor connected Date: Tue, 16 Feb 2016 16:18:21 +0200 Message-ID: <54c075be376ec1001f94a79689b5a8dfa1809692.1455632042.git.jsarha@ti.com> 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 64f1de2..d7b60b4 100644 --- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c +++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c @@ -590,13 +590,20 @@ 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; } @@ -610,10 +617,14 @@ 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;