From patchwork Sat Nov 8 01:06:58 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 5256161 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 4541BC11AC for ; Sat, 8 Nov 2014 01:09:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 596532010F for ; Sat, 8 Nov 2014 01:09:48 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 820BF200DF for ; Sat, 8 Nov 2014 01:09:47 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1XmuUy-0004Bk-QL; Sat, 08 Nov 2014 01:07:28 +0000 Received: from mail-ie0-x230.google.com ([2607:f8b0:4001:c03::230]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XmuUw-0004AH-IY for linux-arm-kernel@lists.infradead.org; Sat, 08 Nov 2014 01:07:27 +0000 Received: by mail-ie0-f176.google.com with SMTP id rd18so6262625iec.21 for ; Fri, 07 Nov 2014 17:07:05 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id; bh=D7FyJQmHo0eQ0piTIxepUT7PY+TnSuuk5rtYsBnV04g=; b=NciW7FXp6XiVgwndlukwXAsIaBP+sNttrbRqCHu/9EEi7eqabWXg8x/VJbC2m1Ns7p I/HKfUL5Q5qmjPgPJLIMvSRfre99tAc7u/PayDwVZcGXDmafmw3W5E1TFMskUJt5wLbo OiIO/kG8fRiG5VpgBUJ3Hmf2v5Xzgv54VXfOg= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=D7FyJQmHo0eQ0piTIxepUT7PY+TnSuuk5rtYsBnV04g=; b=HWMtr6tmwpM0Yi9o9vzicCU9vR5ejoMDQyj8h9TjAr8PNXaCDxx9N4RMiAhKNLoZU7 oZHIdabfXCijCnRl05L+2hYiaJon1TXannyTHonyKymHvfSwXWPMCvVcLyrSJ/ro/4Lc 6xs6TGaIfcyZ76MnsA+eBw7GCbh0Dn8RmePGnNnyE2KUYm6wwSY6A8gPV7Loc60nlm0b SXPVDDqCpnjtFa9bibf1mF4uZiCzoLlEgTuonmgZKItalGLmN37et6MBEXRz2WbelJUC TdJhHP80AwjNTKVd38t2rfVapjNB5TXRaujN8FZ1aqVfB03REk9dWdCALYnIaFTT1HJt i1Sw== X-Gm-Message-State: ALoCoQlmWXw7AiAKbGsx1bgWz7eQ2nE4UmfevkPiuOcOSac/mCpy4rexqn0IFSD13BTqZvFSm2Kf X-Received: by 10.50.112.165 with SMTP id ir5mr8135007igb.44.1415408825808; Fri, 07 Nov 2014 17:07:05 -0800 (PST) Received: from tictac.mtv.corp.google.com ([172.22.65.76]) by mx.google.com with ESMTPSA id i11sm1412722igf.21.2014.11.07.17.07.04 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 07 Nov 2014 17:07:05 -0800 (PST) From: Doug Anderson To: Mike Turquette Subject: [PATCH v2] clk: Propagate prepare and enable when reparenting orphans Date: Fri, 7 Nov 2014 17:06:58 -0800 Message-Id: <1415408818-28028-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 2.1.0.rc2.206.gedb03e5 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141107_170726_732556_EF5780C0 X-CRM114-Status: GOOD ( 15.70 ) X-Spam-Score: -0.8 (/) Cc: Russell King - ARM Linux , Heiko Stuebner , Dmitry Torokhov , Doug Anderson , linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_NONE,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP With the existing code, if you find a parent for an orhpan that has already been prepared / enabled, you won't enable the parent. That can cause later problems since the clock tree isn't in a consistent state. Fix by propagating the prepare and enable. NOTE: this does bring up the question about whether the enable of the orphan actually made sense. If the orphan's parent wasn't enabled by default (by the bootloader or the default state of the hardware) then the original enable of the orphan probably didn't do what the caller though it would. Some users of the orphan might have preferred an EPROBE_DEFER be returned until we had a full path to a root clock. This patch doesn't address those concerns and really just syncs up the state. Tested on rk3288-evb-rk808 by temporarily considering "sclk_tsadc" as a critical clock (to simulate a driver enabling it at bootup). Before: clock enable_cnt prepare_cnt rate accuracy phase ---------------------------------------------------------------------------------------- xin32k 0 0 32768 0 0 sclk_hdmi_cec 0 0 32768 0 0 sclk_otg_adp 0 0 32768 0 0 sclk_tsadc 1 1 993 0 0 After: clock enable_cnt prepare_cnt rate accuracy phase ---------------------------------------------------------------------------------------- xin32k 1 1 32768 0 0 sclk_hdmi_cec 0 0 32768 0 0 sclk_otg_adp 0 0 32768 0 0 sclk_tsadc 1 1 993 0 0 Note that xin32k on rk808 is a clock that cannot be disabled in hardware (it's an always on clock), so really all we needed to do was to sync up the state. Signed-off-by: Doug Anderson --- Changes in v2: - Only do the work for orphans, not for other users of __clk_reparent(). drivers/clk/clk.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 4896ae9..0f04b7c 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -1652,6 +1652,22 @@ void __clk_reparent(struct clk *clk, struct clk *new_parent) __clk_recalc_rates(clk, POST_RATE_CHANGE); } +static void __clk_reparent_orphan(struct clk *clk, struct clk *new_parent) +{ + __clk_reparent(clk, new_parent); + + if (clk->prepare_count) { + unsigned long flags; + + __clk_prepare(new_parent); + + flags = clk_enable_lock(); + if (clk->enable_count) + __clk_enable(new_parent); + clk_enable_unlock(flags); + } +} + /** * clk_set_parent - switch the parent of a mux clk * @clk: the mux clk whose input we are switching @@ -1953,13 +1969,13 @@ int __clk_init(struct device *dev, struct clk *clk) if (orphan->num_parents && orphan->ops->get_parent) { i = orphan->ops->get_parent(orphan->hw); if (!strcmp(clk->name, orphan->parent_names[i])) - __clk_reparent(orphan, clk); + __clk_reparent_orphan(orphan, clk); continue; } for (i = 0; i < orphan->num_parents; i++) if (!strcmp(clk->name, orphan->parent_names[i])) { - __clk_reparent(orphan, clk); + __clk_reparent_orphan(orphan, clk); break; } }