dmatest: make dmatest threads freezable

Making dmatest threads freezable allows its use for system PM testing.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index accc18441b16..eb1d8641cf5c 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -10,6 +10,7 @@
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/dmaengine.h>
+#include <linux/freezer.h>
 #include <linux/init.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
@@ -251,6 +252,7 @@ static int dmatest_func(void *data)
         int                     i;
 
         thread_name = current->comm;
+        set_freezable_with_signal();
 
         ret = -ENOMEM;
 
@@ -305,7 +307,8 @@ static int dmatest_func(void *data)
                 dma_addr_t dma_srcs[src_cnt];
                 dma_addr_t dma_dsts[dst_cnt];
                 struct completion cmp;
-                unsigned long tmo = msecs_to_jiffies(timeout);
+                unsigned long start, tmo, end = 0 /* compiler... */;
+                bool reload = true;
                 u8 align = 0;
 
                 total_tests++;
@@ -404,7 +407,17 @@ static int dmatest_func(void *data)
                 }
                 dma_async_issue_pending(chan);
 
-                tmo = wait_for_completion_timeout(&cmp, tmo);
+                do {
+                        start = jiffies;
+                        if (reload)
+                                end = start + msecs_to_jiffies(timeout);
+                        else if (end <= start)
+                                end = start + 1;
+                        tmo = wait_for_completion_interruptible_timeout(&cmp,
+                                                                end - start);
+                        reload = try_to_freeze();
+                } while (tmo == -ERESTARTSYS);
+
                 status = dma_async_is_tx_complete(chan, cookie, NULL, NULL);
 
                 if (tmo == 0) {