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spi: mediatek: Fix DEVAPC Violation at KO Remove

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[ Upstream commit 0d10e90cee9eb57882b0f7e19fd699033722e226 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Zhichao Liu 2022-11-10 15:28:39 +08:00 committed by Greg Kroah-Hartman
parent d9f0107be1
commit c3b818c91a
1 changed files with 7 additions and 1 deletions
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8
drivers/spi/spi-mt65xx.c
View File

@ -912,14 +912,20 @@ 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);
if (mdata->dev_comp->no_need_unprepare)
clk_unprepare(mdata->spi_clk);
pm_runtime_put_noidle(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return 0;
}