[PATCH AUTOSEL for 4.4 024/101] spi: dw: Disable clock after unregistering the host

Sasha Levin
2018-03-08T05:40:19Z

From: Marek Vasut <marex@denx.de>

[ Upstream commit 400c18e3dc86e04ef5afec9b86a8586ca629b9e9 ]

The dw_mmio driver disables the block clock before unregistering
the host. The code unregistering the host may access the SPI block
registers. If register access happens with block clock disabled,
this may lead to a bus hang. Disable the clock after unregistering
the host to prevent such situation.

This bug was observed on Altera Cyclone V SoC.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/spi/spi-dw-mmio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c
index a6d7029a85ac..581df3ebfc88 100644
--- a/drivers/spi/spi-dw-mmio.c
+++ b/drivers/spi/spi-dw-mmio.c
@@ -120,8 +120,8 @@ static int dw_spi_mmio_remove(struct platform_device *pdev)
{
struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);

- clk_disable_unprepare(dwsmmio->clk);
dw_spi_remove_host(&dwsmmio->dws);
+ clk_disable_unprepare(dwsmmio->clk);

return 0;
}
--
2.14.1