From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751381AbdBTG7S (ORCPT ); Mon, 20 Feb 2017 01:59:18 -0500 Received: from regular1.263xmail.com ([211.150.99.136]:39404 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750926AbdBTG7Q (ORCPT ); Mon, 20 Feb 2017 01:59:16 -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-RL-SENDER: mark.yao@rock-chips.com X-FST-TO: linux-kernel@vger.kernel.org X-SENDER-IP: 58.22.7.114 X-LOGIN-NAME: mark.yao@rock-chips.com X-UNIQUE-TAG: <0c7eb09e71c39daaf1a9575ca4966ff6> X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Subject: Re: [PATCH] drm/rockchip: cdn-dp: Fix error handling To: Christophe JAILLET , airlied@linux.ie, heiko@sntech.de References: <20170219165942.17268-1-christophe.jaillet@wanadoo.fr> <58AA4908.2000808@rock-chips.com> Cc: linux-rockchip@lists.infradead.org, kernel-janitors@vger.kernel.org, linux-arm-kernel@lists.infradead.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org From: Mark yao Message-ID: <58AA938D.5010902@rock-chips.com> Date: Mon, 20 Feb 2017 14:58:21 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2017年02月20日 14:41, Christophe JAILLET wrote: > Le 20/02/2017 à 02:40, Mark yao a écrit : >> On 2017年02月20日 00:59, Christophe JAILLET wrote: >>> It is likely that both 'clk_disable_unprepare()' should be called if >>> 'pm_runtime_get_sync()' fails. >>> >>> Add a new label for that, because 'err_set_rate' is not meaningful >>> in this >>> case. >>> >>> >>> Fixes: 1a0f7ed3abe2 ("drm/rockchip: cdn-dp: add cdn DP support for >>> rk3399") >>> >>> Signed-off-by: Christophe JAILLET >>> --- >>> Not sure but a 'pm_runtime_get_sync()' is maybe also required in the >>> 'err_set_rate' path. >>> --- >>> drivers/gpu/drm/rockchip/cdn-dp-core.c | 3 ++- >>> 1 file changed, 2 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/gpu/drm/rockchip/cdn-dp-core.c >>> b/drivers/gpu/drm/rockchip/cdn-dp-core.c >>> index 9ab67a670885..0fe1ec8b8fb1 100644 >>> --- a/drivers/gpu/drm/rockchip/cdn-dp-core.c >>> +++ b/drivers/gpu/drm/rockchip/cdn-dp-core.c >>> @@ -111,7 +111,7 @@ static int cdn_dp_clk_enable(struct >>> cdn_dp_device *dp) >>> ret = pm_runtime_get_sync(dp->dev); >>> if (ret < 0) { >>> DRM_DEV_ERROR(dp->dev, "cannot get pm runtime %d\n", ret); >>> - goto err_pclk; >>> + goto err_sync; >> >> I think the name err_pm_runtime_get is better. >> err_sync is not a clear name for the pm_runtime_get_sync. >> > I will change it. > >>> } >>> reset_control_assert(dp->core_rst); >>> @@ -133,6 +133,7 @@ static int cdn_dp_clk_enable(struct >>> cdn_dp_device *dp) >>> return 0; >>> err_set_rate: >>> +err_sync: >> >> miss pm_runtime_put, it should be: >> > I am wondering if 'pm_runtime_put_sync' should be added, instead. > We want to revert the 'pm_runtime_get_sync' of line 111. According to > the naming of the function, the _sync version looks more logical to me. > Using ccoccinelle shows that 2/3 of functions calling both > 'pm_runtime_get_sync' and 'pm_runtime_get[_sync]' and using the _sync > variant. > pm_runtime_get_sync will block until hardware actually done power configure, we need make sure power is enable before use the hardware, So we should use pm_runtime_get_sync at power on. At power off time, use pm_runtime_put is enough, it can be async, no need block. Thanks. > Which semantic is the correct one? > > >> err_set_rate: >> pm_runtime_put(dp->dev); >> err_pm_runtime_get: >> clk_disable_unprepare(dp->core_clk); >> err_core_clk: >> >>> clk_disable_unprepare(dp->core_clk); >>> err_core_clk: >>> clk_disable_unprepare(dp->pclk); >> >> > > > > -- Ｍark Yao