From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751882AbdKMDB3 (ORCPT ); Sun, 12 Nov 2017 22:01:29 -0500 Received: from regular1.263xmail.com ([211.150.99.134]:35735 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751293AbdKMDB1 (ORCPT ); Sun, 12 Nov 2017 22:01:27 -0500 X-263anti-spam: KSV:0;BIG:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ADDR-CHECKED4: 1 X-ABS-CHECKED: 1 X-SKE-CHECKED: 1 X-ANTISPAM-LEVEL: 2 X-RL-SENDER: mark.yao@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: mark.yao@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH] drm/rockchip: analogix_dp: Use mutex rather than spinlock To: Enric Balletbo Serra , Emil Renner Berthing Cc: Heiko Stuebner , "open list:ARM/Rockchip SoC..." , linux-kernel References: <20171004175346.11956-1-kernel@esmil.dk> From: Mark yao Message-ID: <65e4cb05-a30c-ba42-ea9c-d7375a7d9769@rock-chips.com> Date: Mon, 13 Nov 2017 11:01:17 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017年11月10日 20:07, Enric Balletbo Serra wrote: > 2017-10-04 19:53 GMT+02:00 Emil Renner Berthing : >> On the Samsung Chromebook Plus I get this error with 4.14-rc3: >> >> BUG: scheduling while atomic: kworker/3:1/50/0x00000002 >> Modules linked in: >> CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 4.14.0-0.rc3-kevin #2 >> Hardware name: Google Kevin (DT) >> Workqueue: events analogix_dp_psr_work >> Call trace: >> [] dump_backtrace+0x0/0x320 >> [] show_stack+0x14/0x20 >> [] dump_stack+0x9c/0xbc >> [] __schedule_bug+0x4c/0x70 >> [] __schedule+0x3f0/0x458 >> [] schedule+0x38/0xa0 >> [] schedule_hrtimeout_range_clock+0x84/0xe8 >> [] schedule_hrtimeout_range+0x10/0x18 >> [] usleep_range+0x64/0x78 >> [] analogix_dp_transfer+0x16c/0x340 >> [] analogix_dpaux_transfer+0x10/0x18 >> [] drm_dp_dpcd_access+0x4c/0xf0 >> [] drm_dp_dpcd_write+0x1c/0x28 >> [] analogix_dp_disable_psr+0x60/0xa8 >> [] analogix_dp_psr_work+0x4c/0x90 >> [] process_one_work+0x1d4/0x348 >> [] worker_thread+0x48/0x478 >> [] kthread+0x12c/0x130 >> [] ret_from_fork+0x10/0x18 >> >> Changing rockchip_dp_device::psr_lock to a mutex rather >> than spinlock seems to fix the issue. >> >> Signed-off-by: Emil Renner Berthing >> --- >> drivers/gpu/drm/rockchip/analogix_dp-rockchip.c | 14 ++++++-------- >> 1 file changed, 6 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c >> index 9606121fa185..d8f72d87ef08 100644 >> --- a/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c >> +++ b/drivers/gpu/drm/rockchip/analogix_dp-rockchip.c >> @@ -72,7 +72,7 @@ struct rockchip_dp_device { >> struct reset_control *rst; >> >> struct work_struct psr_work; >> - spinlock_t psr_lock; >> + struct mutex psr_lock; >> unsigned int psr_state; >> >> const struct rockchip_dp_chip_data *data; >> @@ -83,21 +83,20 @@ struct rockchip_dp_device { >> static void analogix_dp_psr_set(struct drm_encoder *encoder, bool enabled) >> { >> struct rockchip_dp_device *dp = to_dp(encoder); >> - unsigned long flags; >> >> if (!analogix_dp_psr_supported(dp->dev)) >> return; >> >> dev_dbg(dp->dev, "%s PSR...\n", enabled ? "Entry" : "Exit"); >> >> - spin_lock_irqsave(&dp->psr_lock, flags); >> + mutex_lock(&dp->psr_lock); >> if (enabled) >> dp->psr_state = EDP_VSC_PSR_STATE_ACTIVE; >> else >> dp->psr_state = ~EDP_VSC_PSR_STATE_ACTIVE; >> >> schedule_work(&dp->psr_work); >> - spin_unlock_irqrestore(&dp->psr_lock, flags); >> + mutex_unlock(&dp->psr_lock); >> } >> >> static void analogix_dp_psr_work(struct work_struct *work) >> @@ -105,7 +104,6 @@ static void analogix_dp_psr_work(struct work_struct *work) >> struct rockchip_dp_device *dp = >> container_of(work, typeof(*dp), psr_work); >> int ret; >> - unsigned long flags; >> >> ret = rockchip_drm_wait_vact_end(dp->encoder.crtc, >> PSR_WAIT_LINE_FLAG_TIMEOUT_MS); >> @@ -114,12 +112,12 @@ static void analogix_dp_psr_work(struct work_struct *work) >> return; >> } >> >> - spin_lock_irqsave(&dp->psr_lock, flags); >> + mutex_lock(&dp->psr_lock); >> if (dp->psr_state == EDP_VSC_PSR_STATE_ACTIVE) >> analogix_dp_enable_psr(dp->dev); >> else >> analogix_dp_disable_psr(dp->dev); >> - spin_unlock_irqrestore(&dp->psr_lock, flags); >> + mutex_unlock(&dp->psr_lock); >> } >> >> static int rockchip_dp_pre_init(struct rockchip_dp_device *dp) >> @@ -381,7 +379,7 @@ static int rockchip_dp_bind(struct device *dev, struct device *master, >> dp->plat_data.power_off = rockchip_dp_powerdown; >> dp->plat_data.get_modes = rockchip_dp_get_modes; >> >> - spin_lock_init(&dp->psr_lock); >> + mutex_init(&dp->psr_lock); >> dp->psr_state = ~EDP_VSC_PSR_STATE_ACTIVE; >> INIT_WORK(&dp->psr_work, analogix_dp_psr_work); >> >> -- >> 2.14.2 >> > Right this patch fixes the issue for me too. > > Tested-by: Enric Balletbo i Serra > > > Right, it's a bug using spinlock with sleep, Pushed to drm-misc-fixes Thanks. -- Ｍark Yao