linux-kernel - [PATCH 4.18 103/135] clk: x86: Stop marking clocks as CLK_IS

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Message-Id: <20181016170522.446062934@linuxfoundation.org>
Date:   Tue, 16 Oct 2018 19:05:33 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Johannes Stezenbach <js@...21.net>,
        Carlo Caione <carlo@...lessm.com>,
        Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Stephen Boyd <sboyd@...nel.org>,
        Hans de Goede <hdegoede@...hat.com>,
        "David S. Miller" <davem@...emloft.net>,
        Sasha Levin <alexander.levin@...rosoft.com>
Subject: [PATCH 4.18 103/135] clk: x86: Stop marking clocks as CLK_IS_CRITICAL

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Hans de Goede <hdegoede@...hat.com>

[ Upstream commit 648e921888ad96ea3dc922739e96716ad3225d7f ]

Commit d31fd43c0f9a ("clk: x86: Do not gate clocks enabled by the
firmware"), which added the code to mark clocks as CLK_IS_CRITICAL, causes
all unclaimed PMC clocks on Cherry Trail devices to be on all the time,
resulting on the device not being able to reach S0i3 when suspended.

The reason for this commit is that on some Bay Trail / Cherry Trail devices
the r8169 ethernet controller uses pmc_plt_clk_4. Now that the clk-pmc-atom
driver exports an "ether_clk" alias for pmc_plt_clk_4 and the r8169 driver
has been modified to get and enable this clock (if present) the marking of
the clocks as CLK_IS_CRITICAL is no longer necessary.

This commit removes the CLK_IS_CRITICAL marking, fixing Cherry Trail
devices not being able to reach S0i3 greatly decreasing their battery
drain when suspended.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=193891#c102
Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=196861
Cc: Johannes Stezenbach <js@...21.net>
Cc: Carlo Caione <carlo@...lessm.com>
Reported-by: Johannes Stezenbach <js@...21.net>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Acked-by: Stephen Boyd <sboyd@...nel.org>
Signed-off-by: Hans de Goede <hdegoede@...hat.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Sasha Levin <alexander.levin@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 drivers/clk/x86/clk-pmc-atom.c |    7 -------
 1 file changed, 7 deletions(-)

--- a/drivers/clk/x86/clk-pmc-atom.c
+++ b/drivers/clk/x86/clk-pmc-atom.c
@@ -187,13 +187,6 @@ static struct clk_plt *plt_clk_register(
 	pclk->reg = base + PMC_CLK_CTL_OFFSET + id * PMC_CLK_CTL_SIZE;
 	spin_lock_init(&pclk->lock);
 
-	/*
-	 * If the clock was already enabled by the firmware mark it as critical
-	 * to avoid it being gated by the clock framework if no driver owns it.
-	 */
-	if (plt_clk_is_enabled(&pclk->hw))
-		init.flags |= CLK_IS_CRITICAL;
-
 	ret = devm_clk_hw_register(&pdev->dev, &pclk->hw);
 	if (ret) {
 		pclk = ERR_PTR(ret);