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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Vinod Koul <vkoul@kernel.org>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.4 124/183] dmaengine: dw: platform: Switch to acpi_dma_controller_register()
Date:   Tue, 28 Jan 2020 15:05:43 +0100
Message-Id: <20200128135842.295272635@linuxfoundation.org>
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From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

[ Upstream commit e7b8514e4d68bec21fc6385fa0a66797ddc34ac9 ]

There is a possibility to have registered ACPI DMA controller
while it has been gone already.

To avoid the potential crash, move to non-managed
acpi_dma_controller_register().

Fixes: 42c91ee71d6d ("dw_dmac: add ACPI support")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20190820131546.75744-8-andriy.shevchenko@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/dma/dw/platform.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 68a4815750b51..22d0cc1855b5f 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -87,13 +87,20 @@ static void dw_dma_acpi_controller_register(struct dw_dma *dw)
 	dma_cap_set(DMA_SLAVE, info->dma_cap);
 	info->filter_fn = dw_dma_acpi_filter;
 
-	ret = devm_acpi_dma_controller_register(dev, acpi_dma_simple_xlate,
-						info);
+	ret = acpi_dma_controller_register(dev, acpi_dma_simple_xlate, info);
 	if (ret)
 		dev_err(dev, "could not register acpi_dma_controller\n");
 }
+
+static void dw_dma_acpi_controller_free(struct dw_dma *dw)
+{
+	struct device *dev = dw->dma.dev;
+
+	acpi_dma_controller_free(dev);
+}
 #else /* !CONFIG_ACPI */
 static inline void dw_dma_acpi_controller_register(struct dw_dma *dw) {}
+static inline void dw_dma_acpi_controller_free(struct dw_dma *dw) {}
 #endif /* !CONFIG_ACPI */
 
 #ifdef CONFIG_OF
@@ -225,6 +232,9 @@ static int dw_remove(struct platform_device *pdev)
 {
 	struct dw_dma_chip *chip = platform_get_drvdata(pdev);
 
+	if (ACPI_HANDLE(&pdev->dev))
+		dw_dma_acpi_controller_free(chip->dw);
+
 	if (pdev->dev.of_node)
 		of_dma_controller_free(pdev->dev.of_node);
 
-- 
2.20.1