linux-kernel - [PATCH v2 5/7] dmaengine: dw: platform: power on device on shutdown

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]

Date:	Thu, 26 Nov 2015 17:19:11 +0200
From:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	linux-acpi@...r.kernel.org, Vinod Koul <vinod.koul@...el.com>,
	dmaengine@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jarkko Nikula <jarkko.nikula@...ux.intel.com>,
	linux-kernel@...r.kernel.org,
	Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:	Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
Subject: [PATCH v2 5/7] dmaengine: dw: platform: power on device on shutdown

We have to call dw_dma_disable() to stop any ongoing transfer. On some
platforms we can't do that since DMA device is powered off. Moreover we have no
possibility at that point to check if the platform is affected or not. That's
why we call pm_runtime_get_sync() / pm_runtime_put() unconditionally. On the
other hand we can't use pm_runtime_suspended() because runtime PM framework is
not fully used by the driver.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
---
 drivers/dma/dw/platform.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 68a4815..d0734e9 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -239,7 +239,19 @@ static void dw_shutdown(struct platform_device *pdev)
 {
 	struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 
+	/*
+	 * We have to call dw_dma_disable() to stop any ongoing transfer. On
+	 * some platforms we can't do that since DMA device is powered off.
+	 * Moreover we have no possibility to check if the platform is affected
+	 * or not. That's why we call pm_runtime_get_sync() / pm_runtime_put()
+	 * unconditionally. On the other hand we can't use
+	 * pm_runtime_suspended() because runtime PM framework is not fully
+	 * used by the driver.
+	 */
+	pm_runtime_get_sync(chip->dev);
 	dw_dma_disable(chip);
+	pm_runtime_put_sync_suspend(chip->dev);
+
 	clk_disable_unprepare(chip->clk);
 }
 
-- 
2.6.2

--
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/