ACPI: avoid irqrouter_resume might_sleep oops on resume from S4

[linux-2.6-omap-h63xx.git] / drivers / acpi / osl.c

diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c
index b7d1514cd199c834558a416f74dc29a0ab2d88eb..507f051d1cefd437634454809aa69c748f256a0d 100644 (file)
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -746,6 +746,16 @@ acpi_status acpi_os_wait_semaphore(acpi_handle handle, u32 units, u16 timeout)
        ACPI_DEBUG_PRINT((ACPI_DB_MUTEX, "Waiting for semaphore[%p|%d|%d]\n",
                          handle, units, timeout));
 
+       /*
+        * This can be called during resume with interrupts off.
+        * Like boot-time, we should be single threaded and will
+        * always get the lock if we try -- timeout or not.
+        * If this doesn't succeed, then we will oops courtesy of
+        * might_sleep() in down().
+        */
+       if (!down_trylock(sem))
+               return AE_OK;
+
        switch (timeout) {
                /*
                 * No Wait: