drm/i915: add FIFO watermark support
This patch from jbarnes and myself adds FIFO watermark control to the
driver. This is needed for both power saving features on new platforms
with the so-called "big FIFO" and for controlling FIFO allocation
between pipes in multi-head configurations.
It's also necessary infrastructure to support things like framebuffer
compression and configuration supportability checks (i.e. checking a
configuration against available bandwidth).
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index 17b3085..7ba23a6 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -376,11 +376,15 @@
* Clear the PIPE(A|B)STAT regs before the IIR
*/
if (pipea_stats & 0x8000ffff) {
+ if (pipea_stats & PIPE_FIFO_UNDERRUN_STATUS)
+ DRM_DEBUG("pipe a underrun\n");
I915_WRITE(PIPEASTAT, pipea_stats);
irq_received = 1;
}
if (pipeb_stats & 0x8000ffff) {
+ if (pipeb_stats & PIPE_FIFO_UNDERRUN_STATUS)
+ DRM_DEBUG("pipe b underrun\n");
I915_WRITE(PIPEBSTAT, pipeb_stats);
irq_received = 1;
}