drm: introduce drm_can_sleep and use in intel/radeon drivers. (v2)

So we have a few places where the drm drivers would like to sleep to
be nice to the system, mainly in the modesetting paths, but we also
have two cases were atomic modesetting must take place, panic writing
and kernel debugger. So provide a central inline to determine if a
sleep or delay should be used and use this in the intel and radeon drivers.

v2: drop intel_drv.h MSLEEP macro, nobody uses it.

Based on patch from Michel Dänzer <michel.daenzer@amd.com>

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=43941

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

3 files changed, 11 insertions, 8 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 5ac8a164a1ee..1348705faf6b 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -40,7 +40,7 @@
                         ret__ = -ETIMEDOUT;                             \
                         break;                                          \
                 }                                                       \
-                if (W && !(in_atomic() || in_dbg_master())) msleep(W);  \
+                if (W && drm_can_sleep()) msleep(W);    \
         }                                                               \
         ret__;                                                          \
 })
@@ -48,13 +48,6 @@
 #define wait_for(COND, MS) _wait_for(COND, MS, 1)
 #define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
 
-#define MSLEEP(x) do { \
-        if (in_dbg_master()) \
-                mdelay(x); \
-        else \
-                msleep(x); \
-} while (0)
-
 #define KHz(x) (1000*x)
 #define MHz(x) KHz(1000*x)
 
diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index 14cc88aaf3a7..d1bd239cd9e9 100644
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -665,6 +665,8 @@ static void atom_op_delay(atom_exec_context *ctx, int *ptr, int arg)
         SDEBUG("   count: %d\n", count);
         if (arg == ATOM_UNIT_MICROSEC)
                 udelay(count);
+        else if (!drm_can_sleep())
+                mdelay(count);
         else
                 msleep(count);
 }
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index ecd5984ef689..954badb08120 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1696,5 +1696,13 @@ extern void drm_platform_exit(struct drm_driver *driver, struct platform_device
 extern int drm_get_platform_dev(struct platform_device *pdev,
                                 struct drm_driver *driver);
 
+/* returns true if currently okay to sleep */
+static __inline__ bool drm_can_sleep(void)
+{
+        if (in_atomic() || in_dbg_master() || irqs_disabled())
+                return false;
+        return true;
+}
+
 #endif                          /* __KERNEL__ */
 #endif