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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 6FD88C43381 for ; Thu, 28 Feb 2019 15:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2FDF4218AE for ; Thu, 28 Feb 2019 15:09:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551366596; bh=adc0ewNQgrwWLEQlAiEqC0OMasUXRc21drMbgwWYs2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=JebjIDW1mNM0RzdD5MS0aqM/ESYDhtLFw0hpLfn3yKWBdmLBKIO8hDM7RrZ/h+Tpw 3zqCrjiLvYozfs3Jq+thQXKpj4fDC7wZxuECD/TeMuIJld8j/Ih8pjmBpaA99bkvSw QBpkcvMHQnCQ1MmEQZuf08zSIMvR4t1rmCzeMuRc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387617AbfB1PJy (ORCPT ); Thu, 28 Feb 2019 10:09:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:42522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387593AbfB1PJv (ORCPT ); Thu, 28 Feb 2019 10:09:51 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 44DF8218AE; Thu, 28 Feb 2019 15:09:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551366590; bh=adc0ewNQgrwWLEQlAiEqC0OMasUXRc21drMbgwWYs2c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Z9BIF6Zd3VWoSCYYmW4064FZZoVHbIHfHoN+Itb3oDMkDE2cjTHaKveqVdna1Aur7 /B5E7+BFm4CudumLnjkmaLk+0DhRLe39+sKi36vKYoXyx25GK/So014UYdlVeUNOi1 bpEKageuFjrari59+6KLG75qta4t4xHan0gz/q0I= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Paul Kocialkowski , Maxime Ripard , Sasha Levin , dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 4.20 52/81] drm/sun4i: tcon: Prepare and enable TCON channel 0 clock at init Date: Thu, 28 Feb 2019 10:07:44 -0500 Message-Id: <20190228150813.10256-52-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190228150813.10256-1-sashal@kernel.org> References: <20190228150813.10256-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Paul Kocialkowski [ Upstream commit b14e945bda8ae227d1bf2b1837c0c4a61721cd1a ] When initializing clocks, a reference to the TCON channel 0 clock is obtained. However, the clock is never prepared and enabled later. Switching from simplefb to DRM actually disables the clock (that was usually configured by U-Boot) because of that. On the V3s, this results in a hang when writing to some mixer registers when switching over to DRM from simplefb. Fix this by preparing and enabling the clock when initializing other clocks. Waiting for sun4i_tcon_channel_enable to enable the clock is apparently too late and results in the same mixer register access hang. Signed-off-by: Paul Kocialkowski Signed-off-by: Maxime Ripard Link: https://patchwork.freedesktop.org/patch/msgid/20190131132550.26355-1-paul.kocialkowski@bootlin.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/sun4i/sun4i_tcon.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c index f949287d926cd..4e0562aa2cc90 100644 --- a/drivers/gpu/drm/sun4i/sun4i_tcon.c +++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c @@ -760,6 +760,7 @@ static int sun4i_tcon_init_clocks(struct device *dev, return PTR_ERR(tcon->sclk0); } } + clk_prepare_enable(tcon->sclk0); if (tcon->quirks->has_channel_1) { tcon->sclk1 = devm_clk_get(dev, "tcon-ch1"); @@ -774,6 +775,7 @@ static int sun4i_tcon_init_clocks(struct device *dev, static void sun4i_tcon_free_clocks(struct sun4i_tcon *tcon) { + clk_disable_unprepare(tcon->sclk0); clk_disable_unprepare(tcon->clk); } -- 2.19.1