[PATCH] host1x: cdma: use completion instead of semaphore

From: Arnd Bergmann
Date: Mon Dec 10 2018 - 16:51:33 EST


In this usage, the two are completely equivalent, but the
completion documents better what is going on, and we generally
try to avoid semaphores these days.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/gpu/host1x/cdma.c | 6 +++---
drivers/gpu/host1x/cdma.h | 4 ++--
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/host1x/cdma.c b/drivers/gpu/host1x/cdma.c
index 6bfb3e6f43d7..bdc80a303cec 100644
--- a/drivers/gpu/host1x/cdma.c
+++ b/drivers/gpu/host1x/cdma.c
@@ -204,7 +204,7 @@ unsigned int host1x_cdma_wait_locked(struct host1x_cdma *cdma,
cdma->event = event;

mutex_unlock(&cdma->lock);
- down(&cdma->sem);
+ wait_for_completion(&cdma->complete);
mutex_lock(&cdma->lock);
}

@@ -308,7 +308,7 @@ static void update_cdma_locked(struct host1x_cdma *cdma)

if (signal) {
cdma->event = CDMA_EVENT_NONE;
- up(&cdma->sem);
+ complete(&cdma->complete);
}
}

@@ -410,7 +410,7 @@ int host1x_cdma_init(struct host1x_cdma *cdma)
int err;

mutex_init(&cdma->lock);
- sema_init(&cdma->sem, 0);
+ init_completion(&cdma->complete);

INIT_LIST_HEAD(&cdma->sync_queue);

diff --git a/drivers/gpu/host1x/cdma.h b/drivers/gpu/host1x/cdma.h
index c628070b94d7..ba790f9bfebc 100644
--- a/drivers/gpu/host1x/cdma.h
+++ b/drivers/gpu/host1x/cdma.h
@@ -20,7 +20,7 @@
#define __HOST1X_CDMA_H

#include <linux/sched.h>
-#include <linux/semaphore.h>
+#include <linux/completion.h>
#include <linux/list.h>

struct host1x_syncpt;
@@ -70,7 +70,7 @@ enum cdma_event {

struct host1x_cdma {
struct mutex lock; /* controls access to shared state */
- struct semaphore sem; /* signalled when event occurs */
+ struct completion complete; /* signalled when event occurs */
enum cdma_event event; /* event that sem is waiting for */
unsigned int slots_used; /* pb slots used in current submit */
unsigned int slots_free; /* pb slots free in current submit */
--
2.20.0