[PATCH 4.17 001/336] spi: spi-s3c64xx: Fix system resume support

From: Greg Kroah-Hartman
Date: Wed Aug 01 2018 - 13:33:13 EST

4.17-stable review patch. If anyone has any objections, please let me know.


From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

commit e935dba111621bd6a0c5d48e6511a4d9885103b4 upstream.

Since Linux v4.10 release (commit 1d9174fbc55e "PM / Runtime: Defer
resuming of the device in pm_runtime_force_resume()"),
pm_runtime_force_resume() function doesn't runtime resume device if it was
not runtime active before system suspend. Thus, driver should not do any
register access after pm_runtime_force_resume() without checking the
runtime status of the device. To fix this issue, simply move
s3c64xx_spi_hwinit() call to s3c64xx_spi_runtime_resume() to ensure that
hardware is always properly initialized. This fixes Synchronous external
abort issue on system suspend/resume cycle on newer Exynos SoCs.

Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/spi/spi-s3c64xx.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1260,8 +1260,6 @@ static int s3c64xx_spi_resume(struct dev
if (ret < 0)
return ret;

- s3c64xx_spi_hwinit(sdd, sdd->port_id);
return spi_master_resume(master);
#endif /* CONFIG_PM_SLEEP */
@@ -1299,6 +1297,8 @@ static int s3c64xx_spi_runtime_resume(st
if (ret != 0)
goto err_disable_src_clk;

+ s3c64xx_spi_hwinit(sdd, sdd->port_id);
return 0;