VIA_WAIT_ON() is a direct copy of DRM_WAIT_ON() from
drm_os_linux.h.
The copy is made so we can avoid the dependency on the legacy header.
A more involved approach had been to introduce wait_event_* but for this
legacy driver the simpler and more safe approach with a copy of the
macro was selected.
Added the relevant header files for the functions used in VIA_WAIT_ON.
Users of the macro will come in a follow-up patch.
Signed-off-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Kevin Brace <kevinbrace@xxxxxxx>
Cc: Thomas Hellstrom <thellstrom@xxxxxxxxxx>
Cc: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Cc: Mike Marshall <hubcap@xxxxxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Emil Velikov <emil.velikov@xxxxxxxxxxxxx>
Cc: Michel Dänzer <michel@xxxxxxxxxxx>
---
drivers/gpu/drm/via/via_drv.h | 42 ++++++++++++++++++++++++++++++++++-
1 file changed, 41 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/via/via_drv.h b/drivers/gpu/drm/via/via_drv.h
index d5a2b1ffd8c1..664b7f8a20c4 100644
--- a/drivers/gpu/drm/via/via_drv.h
+++ b/drivers/gpu/drm/via/via_drv.h
@@ -24,8 +24,13 @@
#ifndef _VIA_DRV_H_
#define _VIA_DRV_H_
-#include <drm/drm_mm.h>
+#include <linux/jiffies.h>
+#include <linux/sched.h>
+#include <linux/sched/signal.h>
+#include <linux/wait.h>
+
#include <drm/drm_legacy.h>
+#include <drm/drm_mm.h>
#define DRIVER_AUTHOR "Various"
@@ -127,6 +132,41 @@ enum via_family {
#define VIA_WRITE8(reg, val) \
writeb(val, ((void __iomem *)VIA_BASE->handle) + (reg))
+/*
+ * Poll in a loop waiting for 'contidition' to be true.
+ * Note: A direct replacement with wait_event_interruptible_timeout()
+ * will not work unless driver is updated to emit wake_up()
+ * in relevant places that can impact the 'condition'
+ *
+ * Returns:
+ * ret keeps current value if 'condition' becomes true
+ * ret = -BUSY if timeout happens
+ * ret = -EINTR if a signal interrupted the waiting period
+ */
+#define VIA_WAIT_ON( ret, queue, timeout, condition ) \
+do { \
+ DECLARE_WAITQUEUE(entry, current); \
+ unsigned long end = jiffies + (timeout); \
+ add_wait_queue(&(queue), &entry); \
+ \
+ for (;;) { \
+ __set_current_state(TASK_INTERRUPTIBLE); \
+ if (condition) \
+ break; \
+ if (time_after_eq(jiffies, end)) { \
+ ret = -EBUSY; \
+ break; \
+ } \
+ schedule_timeout((HZ/100 > 1) ? HZ/100 : 1); \
+ if (signal_pending(current)) { \
+ ret = -EINTR; \
+ break; \
+ } \
+ } \
+ __set_current_state(TASK_RUNNING); \
+ remove_wait_queue(&(queue), &entry); \
+} while (0)
+
extern const struct drm_ioctl_desc via_ioctls[];
extern int via_max_ioctl;
--
2.20.1
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