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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 15A80C43381 for ; Tue, 12 Mar 2019 18:03:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C776D21734 for ; Tue, 12 Mar 2019 18:03:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552413782; bh=MwyxRwp4FO4eCX0NsEZs7bLe+58Qs93hlmVs7+TTkJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Px1vSStLuq5HWYRg2ERw+POWWW6Uur6bSoH3iZteGwADppR3xgYkVrODhubPEpS6S jyKRhllFGmJVwfafJCGlr5wiT6gzvPKGfuvXPD8ts6+t0EQN5FJtOj656Z+Eh3e/ZR 2zqsYb2Y7S0SdKzWQSEcQJFGc8KvUoZXouBYYbVI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728193AbfCLSDB (ORCPT ); Tue, 12 Mar 2019 14:03:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:49010 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726898AbfCLRM6 (ORCPT ); Tue, 12 Mar 2019 13:12:58 -0400 Received: from localhost (unknown [104.133.8.98]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DEE9B2183F; Tue, 12 Mar 2019 17:12:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1552410778; bh=MwyxRwp4FO4eCX0NsEZs7bLe+58Qs93hlmVs7+TTkJI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ilCiJcwJ7UBII4klL+kL+Ax590NLOQ3rrFFV3NykRkws1XdBM+hnYrSTV3s4UfzFt Ei+CXmpsraBIJY4IbO+HvbxXn3IsohDubd0YegR/xfCSBXWOni+t0xHkwS/bO2VRVp LmmcpblVNyoSY6wcCi909gS4pc8aHKZLmJWATpH0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Paul Kocialkowski , Maxime Ripard , Sasha Levin Subject: [PATCH 4.20 117/171] drm/sun4i: tcon: Prepare and enable TCON channel 0 clock at init Date: Tue, 12 Mar 2019 10:08:17 -0700 Message-Id: <20190312170357.943874725@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190312170347.868927101@linuxfoundation.org> References: <20190312170347.868927101@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ 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 f949287d926c..4e0562aa2cc9 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