linux-kernel - [PATCH 4.1 36/78] mfd: arizona: Fix initialisation of the PM runtime

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20150911224611.472368675@linuxfoundation.org>
Date:	Fri, 11 Sep 2015 15:49:37 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org,
	Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>,
	Lee Jones <lee.jones@...aro.org>
Subject: [PATCH 4.1 36/78] mfd: arizona: Fix initialisation of the PM runtime

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

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

From: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>

commit 72e43164fd472f6c2659c8313b87da962322dbcf upstream.

The PM runtime core by default assumes a chip is suspended when runtime
PM is enabled. Currently the arizona driver enables runtime PM when the
chip is fully active and then disables the DCVDD regulator at the end of
arizona_dev_init. This however has several problems, firstly the if we
reach the end of arizona_dev_init, we did not properly follow all the
proceedures for shutting down the chip, and most notably we never marked
the chip as cache only so any writes occurring between then and the next
PM runtime resume will be lost. Secondly, if we are already resumed when
we reach the end of dev_init, then at best we get unbalanced regulator
enable/disables at work we lose DCVDD whilst we need it.

Additionally, since the commit 4f0216409f7c ("mfd: arizona: Add better
support for system suspend"), the PM runtime operations may
disable/enable the IRQ, so the IRQs must now be enabled before we call
any PM operations.

This patch adds a call to pm_runtime_set_active to inform the PM core
that the device is starting up active and moves the PM enabling to
around the IRQ initialisation to avoid any PM callbacks happening until
the IRQs are initialised.

Signed-off-by: Charles Keepax <ckeepax@...nsource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@...aro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/mfd/arizona-core.c |   14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -912,10 +912,6 @@ int arizona_dev_init(struct arizona *ari
 			     arizona->pdata.gpio_defaults[i]);
 	}

-	pm_runtime_set_autosuspend_delay(arizona->dev, 100);
-	pm_runtime_use_autosuspend(arizona->dev);
-	pm_runtime_enable(arizona->dev);
-
 	/* Chip default */
 	if (!arizona->pdata.clk32k_src)
 		arizona->pdata.clk32k_src = ARIZONA_32KZ_MCLK2;
@@ -1012,11 +1008,17 @@ int arizona_dev_init(struct arizona *ari
 					   arizona->pdata.spk_fmt[i]);
 	}

+	pm_runtime_set_active(arizona->dev);
+	pm_runtime_enable(arizona->dev);
+
 	/* Set up for interrupts */
 	ret = arizona_irq_init(arizona);
 	if (ret != 0)
 		goto err_reset;

+	pm_runtime_set_autosuspend_delay(arizona->dev, 100);
+	pm_runtime_use_autosuspend(arizona->dev);
+
 	arizona_request_irq(arizona, ARIZONA_IRQ_CLKGEN_ERR, "CLKGEN error",
 			    arizona_clkgen_err, arizona);
 	arizona_request_irq(arizona, ARIZONA_IRQ_OVERCLOCKED, "Overclocked",
@@ -1045,10 +1047,6 @@ int arizona_dev_init(struct arizona *ari
 		goto err_irq;
 	}

-#ifdef CONFIG_PM
-	regulator_disable(arizona->dcvdd);
-#endif
-
 	return 0;

 err_irq:

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/