Thread (30 messages) 30 messages, 5 authors, 2016-02-22
STALE3750d

[PATCH 7/7] ARM: OMAP2+: Fix omap_device for module reload on PM runtime forbid

From: Tony Lindgren <tony@atomide.com>
Date: 2016-02-10 23:02:50
Also in: linux-arm-kernel, linux-mmc, linux-omap, linux-serial, linux-spi
Subsystem: arm port, omap2+ support, the rest · Maintainers: Russell King, Aaro Koskinen, Andreas Kemnade, Kevin Hilman, Roger Quadros, Tony Lindgren, Linus Torvalds

If a driver PM runtime is disabled via sysfs, and the module is
unloaded, PM runtime can't do anything to disable the device. Let's
let the interconnect disable the device on BUS_NOTIFY_UNBOUND_DRIVER.

Otherwise omap_device will produce and error on the following module
reload. This can be easily tested with something like:

# modprobe omap_hsmmc
# echo on > /sys/devices/platform/68000000.ocp/4809c000.mmc/power/control
# rmmod omap_hsmmc
# modprobe omap_hsmmc

Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Tero Kristo <redacted>
Reported-by: Ulf Hansson <redacted>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/mach-omap2/omap_device.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
diff --git a/arch/arm/mach-omap2/omap_device.c b/arch/arm/mach-omap2/omap_device.c
index ebd8369..f7ff3b9 100644
--- a/arch/arm/mach-omap2/omap_device.c
+++ b/arch/arm/mach-omap2/omap_device.c
@@ -191,12 +191,22 @@ static int _omap_device_notifier_call(struct notifier_block *nb,
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct omap_device *od;
+	int err;
 
 	switch (event) {
 	case BUS_NOTIFY_DEL_DEVICE:
 		if (pdev->archdata.od)
 			omap_device_delete(pdev->archdata.od);
 		break;
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		od = to_omap_device(pdev);
+		if (od && (od->_state == OMAP_DEVICE_STATE_ENABLED)) {
+			dev_info(dev, "enabled after unload, idling\n");
+			err = omap_device_idle(pdev);
+			if (err)
+				dev_err(dev, "failed to idle\n");
+		}
+		break;
 	case BUS_NOTIFY_ADD_DEVICE:
 		if (pdev->dev.of_node)
 			omap_device_build_from_dt(pdev);
-- 
2.7.0
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