From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0213BC388F9 for ; Sun, 8 Nov 2020 10:47:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6140206ED for ; Sun, 8 Nov 2020 10:47:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728106AbgKHKrt (ORCPT ); Sun, 8 Nov 2020 05:47:49 -0500 Received: from asavdk4.altibox.net ([109.247.116.15]:50076 "EHLO asavdk4.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727348AbgKHKrt (ORCPT ); Sun, 8 Nov 2020 05:47:49 -0500 Received: from ravnborg.org (unknown [188.228.123.71]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by asavdk4.altibox.net (Postfix) with ESMTPS id DD80980518; Sun, 8 Nov 2020 11:47:43 +0100 (CET) Date: Sun, 8 Nov 2020 11:47:42 +0100 From: Sam Ravnborg To: Russell King - ARM Linux admin Cc: Fabio Estevam , Jernej Skrabec , Jonathan Liu , Jonas Karlman , David Airlie , Neil Armstrong , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Andrzej Hajda , linux-rockchip@lists.infradead.org, Boris Brezillon , Laurent Pinchart , Liu Ying , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH] drm: bridge: dw-hdmi: Avoid resetting force in the detect function Message-ID: <20201108104742.GA1161483@ravnborg.org> References: <20201031081747.372599-1-net147@gmail.com> <20201108095322.GA1129714@ravnborg.org> <20201108095724.GW1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201108095724.GW1551@shell.armlinux.org.uk> X-CMAE-Score: 0 X-CMAE-Analysis: v=2.3 cv=VafZwmh9 c=1 sm=1 tr=0 a=S6zTFyMACwkrwXSdXUNehg==:117 a=S6zTFyMACwkrwXSdXUNehg==:17 a=kj9zAlcOel0A:10 a=pGLkceISAAAA:8 a=2388smbMItZUPG-p9eEA:9 a=CjuIK1q_8ugA:10 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Russell, On Sun, Nov 08, 2020 at 09:57:25AM +0000, Russell King - ARM Linux admin wrote: > On Sun, Nov 08, 2020 at 10:53:22AM +0100, Sam Ravnborg wrote: > > Russell, > > > > On Sat, Oct 31, 2020 at 07:17:47PM +1100, Jonathan Liu wrote: > > > It has been observed that resetting force in the detect function can > > > result in the PHY being powered down in response to hot-plug detect > > > being asserted, even when the HDMI connector is forced on. > > > > > > Enabling debug messages and adding a call to dump_stack() in > > > dw_hdmi_phy_power_off() shows the following in dmesg: > > > [ 160.637413] dwhdmi-rockchip ff940000.hdmi: EVENT=plugin > > > [ 160.637433] dwhdmi-rockchip ff940000.hdmi: PHY powered down in 0 iterations > > > > > > Call trace: > > > dw_hdmi_phy_power_off > > > dw_hdmi_phy_disable > > > dw_hdmi_update_power > > > dw_hdmi_detect > > > dw_hdmi_connector_detect > > > drm_helper_probe_detect_ctx > > > drm_helper_hpd_irq_event > > > dw_hdmi_irq > > > irq_thread_fn > > > irq_thread > > > kthread > > > ret_from_fork > > > > > > Fixes: 381f05a7a842 ("drm: bridge/dw_hdmi: add connector mode forcing") > > > Signed-off-by: Jonathan Liu > > > > you are the original author of this code - any comments on this patch? > > No further comments beyond what has already been discussed, and the > long and short of it is it's been so long that I don't remember why > that code was there. Given that, I'm not even in a position to ack > the change. Sorry. Thanks for the quick reply. Given that this fixes a problem for Jonathan I will apply this to -fixes if there is no other feedback the next couple of days. If it introduces regression we can take it from there. Jonathan - please ping me if I forget. Sam