[PATCH 3.16 202/328] spi: rspi: Fix invalid SPI use during system suspend

[Ben Hutchings]

3.16.62-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

commit c1ca59c22c56930b377a665fdd1b43351887830b upstream.

If the SPI queue is running during system suspend, the system may lock
up.

Fix this by stopping/restarting the queue during system suspend/resume,
by calling spi_master_suspend()/spi_master_resume() from the PM
callbacks.  In-kernel users will receive an -ESHUTDOWN error while
system suspend/resume is in progress.

Based on a patch for sh-msiof by Gaku Inami.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/spi/spi-rspi.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -1158,6 +1158,29 @@ static struct platform_device_id spi_dri
 
 MODULE_DEVICE_TABLE(platform, spi_driver_ids);
 
+#ifdef CONFIG_PM_SLEEP
+static int rspi_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct rspi_data *rspi = platform_get_drvdata(pdev);
+
+	return spi_master_suspend(rspi->master);
+}
+
+static int rspi_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct rspi_data *rspi = platform_get_drvdata(pdev);
+
+	return spi_master_resume(rspi->master);
+}
+
+static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
+#define DEV_PM_OPS	&rspi_pm_ops
+#else
+#define DEV_PM_OPS	NULL
+#endif /* CONFIG_PM_SLEEP */
+
 static struct platform_driver rspi_driver = {
 	.probe =	rspi_probe,
 	.remove =	rspi_remove,
@@ -1165,6 +1188,7 @@ static struct platform_driver rspi_drive
 	.driver		= {
 		.name = "renesas_spi",
 		.owner	= THIS_MODULE,
+		.pm = DEV_PM_OPS,
 		.of_match_table = of_match_ptr(rspi_of_match),
 	},
 };