spi: spi-s3c64xx: Fix system resume support

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@samsung.com>
CC: <stable@vger.kernel.org> # 4.10.x: 1c75862d8e5a spi: spi-s3c64xx: Remove unused s3c64xx_spi_hwinit()
CC: <stable@vger.kernel.org> # 4.10.x
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Andi Shyti <andi@etezian.org>
Change-Id: I34cb90a7eff4bf21162c232eb6308fb120d06d4a

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 0bc0a84..b525f94 100644 (file)
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1334,8 +1334,6 @@ static int s3c64xx_spi_resume(struct device *dev)
        if (ret < 0)
                return ret;
 
-       s3c64xx_spi_hwinit(sdd);
-
        return spi_master_resume(master);
 }
 #endif /* CONFIG_PM_SLEEP */
@@ -1372,6 +1370,9 @@ static int s3c64xx_spi_runtime_resume(struct device *dev)
        ret = clk_prepare_enable(sdd->clk);
        if (ret != 0)
                goto err_disable_src_clk;
+
+       s3c64xx_spi_hwinit(sdd);
+
        /*
         *  A workaround to prevent issues in the H/W handover between this
         *  driver and the FIMC-IS firmware.