Unverified Commit 0d10e90c authored by Zhichao Liu's avatar Zhichao Liu Committed by Mark Brown
Browse files

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: default avatarZhichao Liu <zhichao.liu@mediatek.com>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20221110072839.30961-1-zhichao.liu@mediatek.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent bff6bef7

drivers/spi/spi-mt65xx.c

+7 −1
Original line number Diff line number Diff line
@@ -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;

}