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authorZhichao Liu <zhichao.liu@mediatek.com>2022-11-10 15:28:39 +0800
committerMark Brown <broonie@kernel.org>2022-11-10 10:25:12 +0000
commit0d10e90cee9eb57882b0f7e19fd699033722e226 (patch)
tree01b33e7be5ed76d57a0b47ee1b568eec2efbf46d /drivers/spi
parentbff6bef701db784bb159a659e99c785b4594fc96 (diff)
downloadlinux-0d10e90cee9eb57882b0f7e19fd699033722e226.tar.gz
spi: mediatek: Fix DEVAPC Violation at KO Remove
A DEVAPC violation occurs when removing the module
due to accessing HW registers without base clock.
To fix this bug, the correct method is:
1. Call the runtime resume function to enable the
   clock;
2. Operate the registers to reset the HW;
3. Turn off the clocks and disable the device
   RPM mechanism.

Signed-off-by: Zhichao Liu <zhichao.liu@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221110072839.30961-1-zhichao.liu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/spi-mt65xx.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index a33c9a3de395..d6aff909fc36 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -1273,8 +1273,11 @@ static int mtk_spi_remove(struct platform_device *pdev)
 {
 	struct spi_master *master = platform_get_drvdata(pdev);
 	struct mtk_spi *mdata = spi_master_get_devdata(master);
+	int ret;
 
-	pm_runtime_disable(&pdev->dev);
+	ret = pm_runtime_resume_and_get(&pdev->dev);
+	if (ret < 0)
+		return ret;
 
 	mtk_spi_reset(mdata);
 
@@ -1283,6 +1286,9 @@ static int mtk_spi_remove(struct platform_device *pdev)
 		clk_unprepare(mdata->spi_hclk);
 	}
 
+	pm_runtime_put_noidle(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
 	return 0;
 }