PM / Clocks: Only disable enabled clocks in pm_clk_suspend()

From: Magnus Damm <[email protected]>

Refrain from running clk_disable() on clocks that have not been enabled. A typical case when this can happen is during Suspend-to-RAM for devices that have no driver associated with them. In such case the clock may be in default ACQUIRED state.

Without this patch the sh7372 Mackerel board crashes in __clk_disable() during Suspend-to-RAM with:
"Trying to disable clock 0xdeadbeef with 0 usecount" This happens for the CEU device which is added during boot. The test case has no CEU driver included in the kernel configuration. Needed for v3.2-rc1.

Signed-off-by Magnus Damm <[email protected]>

---

 drivers/base/power/clock_ops.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

drivers/base/power/clock_ops.c +2 -2

@@ -229,7 +229,8 @@ int pm_clk_suspend(struct device *dev)
 
 	list_for_each_entry_reverse(ce, &psd->clock_list, node) {
 		if (ce->status < PCE_STATUS_ERROR) {
-			clk_disable(ce->clk);
+			if (ce->status = PCE_STATUS_ENABLED)
+				clk_disable(ce->clk);
 			ce->status = PCE_STATUS_ACQUIRED;
 		}
 	}
--

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